[1]

A PROJECT REPORT ON

DIELECTRIC PROPERTIES

OF

CERAMIC MATERIALS

Submitted in partial fulfillment

of the requirement for the award of

First Degree Programme in Physics under CBCSS

Of

UNIVERSITY OF KERALA

By

Jeenamol Nizam

Reg.No.230-12113014

Associated with

Chippy Mohan

Veena.S.V

Arun.A.L

DEPARTMENT OF PHYSICS

IQBAL COLLEGE

PERINGAMMALA

THIRUVANANTHAPURAM

2015

[2]

Department of Physics

Iqbal College

Peringammala

CERTIFICATE

Certified that the project entitled “DIELECTRIC PROPERTIES OF CERAMIC

MATERIALS” is an authentic record of the work carried out by……Jeenamol

Nizam……Reg.No….230-12113014….in partial fulfillment of the requirement for the award of

First Degree Programme in Physics under CBCSS of University of Kerala.

Dr.L.ABDULKHALAM

Head of the Dept.

Iqbal College

Peringammala

Examiners

[3]

DECLARATION

I Jeenamol Nizam hereby declare that this project entitled “DIELECTRIC PROPERTIES OF

CERAMIC MATERIALS” is an authentic report of the work done by me under the guidance of

Dr.L.ABDULKHALAM (Head of the Department, Iqbal College Peringammala).

Peringammala Jeenamol nizam

[4]

ACKNOWLEDGEMENT

It is with great pleasure that I record here my deep sense of gratitude to all those who had

given me valuable guidance, constant encouragement and support all along the course of this

project work. I take this opportunity to record my sincere thanks to Dr.L.ABDUL KHALAM,

Head of the Department of Physics, Iqbal College Peringammala for suggesting and guiding us

throughout the work. I would also like to acknowledge my sincere gratitude to Paarvathy teacher

and all other staffs for providing the necessary facilities and aids to carry out this project work.

Here I would like to record the encouragement, support and co-operation given to me by my

teachers, colleagues and parents. It was their wishes and untiring support that helped me to

complete this work and it is beyond words to express my feelings towards them.

Peringammala, Jeenamol Nizam

[5]

ABOUT THE PROJECT

DIELECTRIC PROPERTIES OF

CERAMIC MATERIALS

Nowadays, we all are familiar with the applications and usage of dielectrics. Most of which

are used in electronic and industrial applications. Mica, paper, glass, plastics, oxides of various

metals etc. are the currently used dielectrics. But most of these are expensive, rarely available and

the process of preparing these is very costly. Ceramic materials are also used as dielectrics. Here

we used to study about the dielectric properties by using biological ceramic samples and also to

study about the current applications of these materials. The biological sample that we had chosen

for our experimental study is the eggshell. If it is possible to use this as a dielectric, we can replace

other costly dielectric materials by this. The main advantage of this is that, it is easily available,

eco-friendly, inexpensive etc. Because of all these positive factors we had chosen the eggshell as

the sample for my project.

[6]

CONTENTS

CHAPTER 1

INTRODUCTION

1.1 CERAMIC MATERIALS

1.2 INSTRUMENTS AND MEASUREMENTS

1.3 MATERIAL PREPARATION

1.4 EGG SHELL

CHAPTER 2

EXPERIMENTAL PROCEDURE

2.1 SELECTION OF SAMPLE AND POWDER FORMING

2.2 CALCINATION

2.3 FORMING

2.4 PELLATIZING

2.5 SINTERING

[7]

CHAPTER 3

RESULT AND CONCLUSION

3.1 PARALLEL CAPACITANCE

3.2 SERIES CAPACITANCE

3.3 PARALLEL RESISTANCE

3.4 SERIES RESISTANCE

3.5 PARALLEL INDUCTANCE

3.6 SERIES INDUCTANCE

3.7 QUALITY FACTOR

CONCLUSION

REFERENCE

[8]

CHAPTER 1

INTRODUCTION

1.1 CERAMICS

The subject of ceramics covers a wide range of materials. Recent attempts have been made

to divide in to two parts: Traditional ceramics and advanced ceramics. Traditional ceramics bear

a close relationship to those materials that have been developed since the earliest civilization. They

are pottery, structural clay products and clay based refractories with which we may also group

cements and concretes and glasses. Whereas traditional ceramics still represent a major parts of

ceramic industry .Advanced ceramics are classified in to two, Functional ceramics and Structural

ceramics. Advanced ceramics used for electrical, magnetic, electronic and optical applications are

sometimes referred to as Functional ceramics. And for structural applications at ambient as well

as elevated temperatures are referred as structural ceramics.

Chemically, with the exception of carbon, ceramics are non-metallic

inorganic compounds. Examples are the Silicates such as Kaolinites (Al2Si2O5(OH)4) and Mullet

(Al6Si2O13) Simple oxides such as alumina(Al2O3) and Zirconia(ZrO2) . Complex oxides other

than the silicates such as Barium Titan ate (BaTiO3) and the superconducting material

YBa2Cu3O6+$ .In addition there are non-oxides including carbides, nitrides , borides , silicates

[9]

and halides .There are also compounds based on nitride oxide or oxy nitride systems . Example;

Beta – silicon’s the general formula Si6-zAlzN8-ZOZ .

Structurally, all materials are either crystalline or amorphous. Amorphous materials are

also referred to as glassy. The difficulty and expense of growing single crystals means that,

normally, crystalline ceramics are actually poly crystalline, they are made up of a large number

of small crystals or grains separated from one another by grain boundaries. In ceramics we are

concerned with two types of structures both of which have found effect on properties. The first

type of structure is at the atomic scale: the type of bonding and the crystal structure (for a

crystalline ceramic) or amorphous structure (if it is glassy). The second type of structure is at a

larger scale: the micro structure which refers to the nature quantity and distribution of the structural

elements or phases in the ceramics (crystal, glass and porosity)

It is sometime useful distinguish between the intrinsic properties of a material and the

properties that depend on the micro structure. The intrinsic properties are determined by the

structure at the atomic scale and are properties that are not susceptible to significant change by

modification of the micro structure, properties, such as the melting point elastic modulus, co-

efficient of thermal expansion and whether the metal is brittle, magnetic, Ferro electrical or semi

conducting. In contrast many of the properties critical to the engineering applications of materials

are strongly dependent on the microstructure example: mechanical strength dielectric constant, and

electrical conductivity.

Intrinsically, ceramics usually have high melting points and are therefore

generally described as highly refractory. There are also usually hard, brittle and chemically

[10]

insert. This chemical inertness is usually taken for granted, for example: in ceramic and glass table

ware and in the bricks mortar and glass of our houses. However when used at high temperature as

in the chemical and metallurgical industries, thus chemical inertness is severally tried.

The electrical, magnetic and dielectrically behavior covers a wide range – for example: in

the case of electrical behavior from insulators to conductors. The applications of ceramics are

many. Usually for a given application one property may be of particular importance, but in facts

all relevant properties need to be considered. We are therefore usually interests in combinations of

properties. For traditional ceramics and glasses, familiar applications include structural building

material refractors for furnace lining, table ware and sanitary ware, electrical insulation (electrical

porcelain and steatite) glass container and glass for building and transportation vehicle.

Table1.1.1 Applications of some advanced ceramics are shown in the table.

Functions Ceramic Applications

Electric Ferro electric materials

(BaTio3 ,SrTio3)

Piezoelectric materials

(PZT)

Ion conducting material

(Beta –Al2O3, ZrO2)

Ceramic capacitor Vibrato, oscillator, filter etc.

Transduce Ultrasonic humifier. Piezoelectric spark

generator, etc. Solid electrolyte for sodium battery,

ZrO2 ceramics: oxygen Sensor, pH meter fuel cells

[11]

Magnetic Soft ferrite

Hard ferrite

Magnetic recording head, temperature sensor, etc.

Ferrite magnet , fractional horse power motors , etc.

Optical Translucent alumina.

Translucent Mg-Al

spinel, mulle , etc.

PLZT ceramics

High pressure sodium vapor lamp for a lighting tube.

Special purpose lamp , infrared transmission window

materials.

Light memory element , video display and storage

system , light modulation element , light shutter , light

valve

Chemical Gas sensor

ZnO,Fe2O3, SnO2

Organic catalyst

Humidity censor

Gas leakage alarm, automatic ventilation fan,

hydrocarbon, fluorocarbon detectors etc. Enzyme

carrier, Zeolites. Cooking control elements in

microwave oven , etc.

Thermal ZrO2, TiO2 Infrared radiator

Mechanical Wear-resistant material

(Al2O3,ZrO2)

Heat – resistant materials

(SiC, Al2O3, Si3N4)

Mechanical seal, ceramic liner, bearings thread

guide, pressure sensors. Ceramic engine , turbine

blade heat exchangers ,welding burner nozzle , high-

frequency combustion crucibles

Biological Alumina ceramics

implantation,

Hydroxyapatite bio gas

Artificial tooth root, bone, and joint.

[12]

CERAMIC FABRICATION

Chemical composition

Ceramic fabrication (Intrinsic)

Microstructure Properties

Figure1.1.1 The important relationship in ceramic fabrication

The important relationship between chemical composition, atomic structure, fabrication

microstructure and properties of polycrystalline ceramics are illustrated in figure 1.1. The intrinsic

properties must be considered at the time of material selection. The properties of ceramic materials

depend on the microstructure such as grain size, porosity and the presence of any secondary phases.

The overall fabrication method can be divided into few several discreet steps and are referred to

us processing steps.

[13]

CERAMIC FABRICATION PROCESS

Ceramics can be fabricated by a variety of methods. The fabrication methods can be

divided in to three groups depending on whether the starting material involves a gaseous phase,

a liquid phase or solid phase.

A) Gas- phase reactions

The category of methods based on the use of gaseous starting materials can involve

reactions between a gas and a liquid or reactions between a gas and a solid. By far the most

important are Chemical Vapor Deposition methods. Where the desired material is formed by

chemical reaction between gaseous species. The fabrication route involving gas, liquid reactions

has been shown to offer some promise only recently and referred to us Directed Metal Oxidation.

Reaction between a gas and a solid referred to us Reaction Bonding.

B) Liquid Precursor Methods

Methods in which a solution of metal compounds is converted in to solid body are

sometimes referred to as liquid precursor methods. A liquid precursor route that has attracted

intense interest since the mid 1970 s is the Sol Gel Process. Chemical composition consisting of

simple or complex oxides is produced by this route. Another route that has attracted a fair degree

of interest in the past 20 years is Polymer Pyrolysis. In which non – oxides are produced by

pyrolysis of suitable polymers.

[14]

C) Fabrication from Powders

This route involves the production of the desired body from an assemblage of finely

divided solids that is powders by the action of heat. It gives rise to the two most widely used

methods for fabrication of ceramics. (1) Melt Casting and (2) Firing of Compacted Powders.

These two fabrication routes have either origin in the earliest civilization.

1.2 INSTRUMENTS AND MEASUREMENTS

HOT AIR OVEN

Hot air ovens are electrical devices used in sterilization. They were originally developed

by Pasteur. The oven uses dry heat to sterilize articles. Generally, they can be operated from 50 to

3000C (122 to 5720F). There is a thermostat controlling the temperature. These are digitally

controlled to maintain the temperature. Their double walled insulation keeps the heat in and

conserves energy, the inner layer being a poor conductor and outer layer being metallic. There is

also an air filled space in between to aid insulation. An air circulating fan helps in uniform

distribution of the heat. These are fitted with the adjustable wire mesh plated trays or aluminum

trays and may have an on/off rocker switch, as well as indicators and controls for temperature and

holding time. The capacities of these ovens vary. Power supply needs vary from country,

depending on the voltage and frequency (hertz) used. Temperature sensitive tapes or other devices

like those using bacterial spores can be used to work as controls, to test for the efficacy of the

device in every cycle.

[15]

Figure1.2.1; HOT AIR OVEN

MAGNETIC STIRRER

It is used to prepare 0.3 weigh % PVA solution. A magnetic stirrer or

magnetic mixer is a laboratory device that employs a rotating magnetic field to cause a stir bar

(also called “flea”) immersed in a liquid to spin very quickly, thus stirring it. The rotating field

may be created either by a rotating magnet or a set of stationary electromagnets, placed beneath

the vessel with the liquid. Since glass does not affect a magnetic field appreciably (it is transparent

to magnetism), and most chemical reactions take place in glass vessels, magnetic stir bars work

well in glass vessels. On the other hand, the limited size of the bar means that magnetic stirrers

can only be used for relatively small experiments. They also have difficulty dealing with viscous

liquids or thick suspensions. For larger volumes or more viscous liquids. Some sort of mechanical

stirring is typically needed.

[16]

Magnetic stirrers are often used in chemistry and biology. They are

preferred over gear-driven motorized stirrers because they are quieter, more efficient, and have no

moving external parts to break or wear out. Because of its small size, a stirring bar is more easily

cleaned and sterilized than other stirring devices. They do not require lubricants which could

contaminate the reaction vessel and the product. They can be used inside hermetically closed

vessels or systems, without the need for complicated rotary seals. Magnetic stirrers may also

include a hot plate or some other means for heating the liquid.

Figure1.2.2; MAGNETIC STIRRER

[17]

MUFFLE FURNACE

A muffle furnace in historic usage is a furnace in which the subject material is isolated

from the fuel and all of the products of combustion including gases and flying ash. After the

development of high-temperature electric heating elements and widespread electrification in

developed countries, new muffle furnaces quickly moved to electric designs.

Today, a muffle furnace is a front-loading box-type oven or kiln for

high-temperature applications such as fusing glass, creating enamel coatings, ceramics and

soldering and brazing articles. They are also used in many research facilities, for example by

chemists in order to determine what proportion of a sample is non-combustible and non-volatile.

Some digital controllers allow RS232 interface and permit the operator to program up to 126

segments, such as molybdenum silicide, can now produce working temperatures up to 1,800

degrees Celsius (3,272 degrees Fahrenheit), which facilitate more sophisticated metallurgical

applications.

The term muffle furnace may also be used to describe another oven constructed on many

of the same principles as the box type kiln mentioned above, but takes the form of a long , wide,

and thin hollow tube used in roll to roll manufacturing processes.

Both of the above mentioned furnaces are usually heated to desired temperatures by

conduction, convection, or blackbody radiation from electrical resistance heating elements.

Therefore there is no combustion involved in the temperature control of the system, which

[18]

allows for much greater control of temperature uniformity and assures isolation of the material

being heated from the byproducts of fuel combustion.

Figure1.2.3; MUFFLE FURNACE

BOX FURNACE

Euro herm, PID programmable digital temperature indicator cum controller is used

for calcination and sintering process for molybdenum silicide heating elements from USA is used.

FEATURES

● Three control options

● Controlled heat-up rate eliminates thermal shock to materials

[19]

●Quick heat-up and cool-down rates

●Energy efficient Moldatherma insulation with fully embedded heating element

●Unique double-walled box furnace construction minimizes exterior surface temperatures for

operator safety and energy efficiency

●Box Furnace has a side-hinged door for convenient operation and full chamber access

●Long-life Type “K” thermocouple

●Air vent (1” dia., top) and air inlet(.375”dia.,rear) for inert atmosphere exchange

●Removable and replaceable Moldatherma hearth plate supports load and prevents damage to your

box furnace due to spillage

●Main power on/off switch on control panel

●Box Furnace has a safety door is opened; helping to protect the box furnace heating element and

minimizes possible exposure to the user

●Available in 120V and 208/240V configurations

HYDRAULIC PRESS

A hydraulic press is a device using a hydraulic cylinder to generate a compressive force. It

uses the hydraulic equivalent of a mechanical lever, and was also known as a Brahma press after

the inventor, Joseph Brahma, of England. He invented and was issued a patent on this press

[20]

in 1795. As Brahma installed toilets, he studied the existing literature on the motion of the fluids

and put this knowledge into the development of press.

Figure1.2.4; HYDRAULIC PRESS

PRINCIPLE

The hydraulic press depends on Pascal’s principle: the pressure throughout a closed system

is constant. One part of the system is a piston acting as a pump, with a modest mechanical force

acting on a small cross-sectional area; the other part is a piston with a larger area which generates

a correspondingly large mechanical force. Only small-diameter tubing is needed if the pump is

separated from the press cylinder. Pascal’s law: Pressure on a confined fluid is transmitted

undiminished and acts with equal force on equal areas and at 90 degrees to

[21]

the container wall. A fluid, such as oil, is displaced when either piston is pushed inward. Since

the fluid is incompressible, the volume that the small piston displaces is equal to the volume

displaced by the large piston. This causes a difference in the length of displacement, which is

proportional to the ratio of areas of the heads of the pistons given that volume=area X length.

Therefore, the small piston must be moved a large piston will move is the distance that the small

piston is moved divided by the ratio of the areas of the heads of the pistons. This is how energy,

in the form of work in this case, is conserved and the Law of Conservation of Energy is satisfied.

Work is force applied over a distance, and since the force is increased on the larger piston, the

distance the force is applied over must be decreased

APPLICATIONS

Hydraulic presses are commonly used for forging, clinching, molding, blanking ,

punching, deep drawing, and metal forming operations.

SOURCE METER

The Key sight B2901A precision source/ Measure Unit (SMU) are a 1 channel, compact

and cost-effective bench-top SMU with the capability to source and measure both voltage and

current. It is versatile to perform I/V (current vs. voltage) measurement easily with high accuracy.

Integration of 4 quadrants source and measurement capabilities enables I/V measurement simply

and easily without configuring multiple instruments. The wide coverage of 210V, 3 A DC/10.5A

pulse with a single instrument minimizes the investment. Minimum 100fA/100nV measurement

resolution support accurate characterization of DUT. The superior

[22]

4.3’ color display and various view modes improve productivity for test, debug and

characterization with intuitive operation.

MEASUREMENT CAPABILITIES

●Supports one-channel configuration.

●Minimum source resolution: 1pA/1 micro Volt, Minimum measurement resolution:

200fA/100nV.

●Maximum output: 210V, 3 A DC/10.5 A pulse

●Arbitrary waveform generation and digitizing capabilities from 2D micro second interval.

GENERAL FEATURES

● Integrated 4-quadrants source and measurement capabilities.

●The 4.3’ color display supports both graphical and numerical view modes

●Free application software to facilitate PC-base instrument control.

●High throughout and SCPI command supporting conventional SMU command set.

LCR-HIGHTESTER 3532-50

With variable frequency measurements, the highly acclaimed 3522/3532 LCR High Tester

has been improved with the power for maximum high speed measurements of 5ms. This means

that line tact times can be further shortened, promising you increased line efficiency.

[23]

The 3522-50 offers DC and a range from 1mHz to 100kHz, and the 3532-50 covers the

range from 42Hz to 5MHz. Test conditions can now come closer to a components operating

conditions. The high basic accuracy of +0.08% or -0.08%, combined with ease of use and low

price give these impedance meters outstanding cost-performance characteristics.

Measurement frequency, measurement signal levels, and other measurement conditions

can be changed while monitoring the measurement results, enabling effective trial measurements

and setting of evaluation conditions. Operation is extremely simple: touch the item on the screen

to be changed, and the possible settings appear in sequence. The neat and simple front panel

eliminates all key switches, for a clutter-free design. Up to thirty sets of measurement conditions,

including comparator values, provide rapid response to constantly changing components on

flexible production lines. With multiple measurement conditions in memory, up to five different

measurements can be made sequentially. The comparator function lets a single unit provide the

logical AND result for this sequence of tests.

Figure1.2.7; LCR HIGHTESTER

[24]

1.3 MATERIAL PREPARATION

CALCINATION

Calcination is a thermal treatment process to bring about a thermal decomposition. In other

hand ‘Heating to high temperatures in air or oxygen. This process takes place below the melting

point of the product. Also used to heat materials that are fine and dusty, sensitive to oxidation,

combustible, explosive, potentially contaminating or thermally sensitive, rotary calciners isolate

the materials to be processed in a high-temperature chamber. The name calcination is derived from

the Latin word ‘Calcinare’ which mean to burn lime. Calcination is also used to mean a thermal

treatment process in the absence or limited supply of air or oxygen applied to ores and other solid

materials to bring about a thermal decomposition, phase transition, or removal of a volatile

fraction. The calcination process normally takes place at temperatures below the melting point of

the product materials. Calcination is not the same process as roasting. In roasting, more complex

gas–solid reactions take place between the furnace atmosphere and the solids. Calcination takes

place inside equipment called calciners. A calciner is a steel cylinder that rotates inside a heated

furnace and performs indirect high-temperature processing (1000-2100 °F) within a controlled

atmosphere

[25]

Calcium carbonate is a naturally occurring mineral. It exists nearly all over the world. The

chemical composition of this mineral varies greatly from region to region as well as between

different deposits in the same region. Therefore, the end product from each natural deposit is

different. Calcination was performed in the furnace at 848°C for 2 h after crushing the dried waste

eggshell typically eggshell is composed of calcium carbonate (CaCO3). Calcination reactions

usually take place at or above the thermal decomposition temperature or the transition temperature.

This temperature is usually defined as the temperature at which the standard Gibb's free energy of

reaction for a particular calcination reaction is equal to zero. Calcination reactions usually take

place at or above the thermal decomposition temperature. This temperature is usually defined as

the temperature at which the standard Gibbs free energy is equal to zero.

These methods, involving decomposition of solids or chemical reaction between solids

are referred to in the ceramic literature as calcination.

In some cases, calcination of a metal results in oxidation of the metal. Jean Rey noted

that lead and tin when calculated gained weight, presumably as they were being oxidized

POLYVINYL ALCOHOL

Polyvinyl alcohol is a water-soluble synthetic polymer. It has the idealized formula

[CH₂CH] x. It is used in papermaking, textiles, and a variety of coatings. It is white and odorless.

It is sometimes supplied as beads or as solutions in water.

1. Formula: (C2H4O)x

2. Melting point: 230 °C

[26]

3. Density: 1.19 g/cm³

4. Boiling point: 228 °C

5. Soluble in: Water

Description

Polyvinyl alcohol for food use is an odorless and tasteless, translucent, white or cream

colored granular powder. It is soluble in water, slightly soluble in ethanol, but insoluble in other

organic solvents. Typically a 5% solution of polyvinyl alcohol exhibits a pH in the range of 5.0 to

6.5. Polyvinyl alcohol has a melting point of 180 to 190°C. It has a molecular weight of between

26,300 and 30,000, and a degree of hydrolysis of 86.5 to 89%.

In this project, adding PVA is adding with the Polyvinyl alcohol have been used for

ceramic material When the reaction is allowed to proceed to completion, the product is highly

soluble in water and insoluble in practically all organic solvents. Incomplete removal of the acetate

groups yields resins less soluble in water and more soluble in certain organic liquids. Polyvinyl

alcohols are water-soluble polymers manufactured by alcoholysis of polyvinyl acetate. The

properties of the various grades are mainly governed by the molecular weight and the remaining

content of acetyl group

Polyvinyl Alcohol as a binder in Ceramic Bodies

Usually it is used as a binder for glazes, during glazing operations, before the screen printer

(a water solution of polyvinyl alcohol is sprayed on the surface to be decorated). It is a strong

surfactant and binding power is connected to its ability to wet particles (products having a low

molecular weight exhibit low viscosities and they have a minimal effect on the viscosity of

[27]

glazes or body slips). It is stable because it does not ferment. Usually suppliers propose water

solutions of polyvinyl alcohol.

SINTERING

Sintering is a heat treatment applied to a powder compact in order to impart strength and

integrity. The temperature used for sintering is below the melting point of the major constituent of

the Powder Metallurgy material.

After compaction, neighboring powder particles are held together by cold welds, which give the

compact sufficient “green strength” to be handled. At sintering temperature, diffusion processes

cause necks to form and grow at these contact points.

There are two necessary precursors before this "solid state sintering" mechanism can take place:-

● Removal of the pressing lubricant by evaporation and burning of the vapors

●Reduction of the surface oxides from the powder particles in the compact.

The goal of any sintering furnace is to provide a consistent, repeatable and economical

relationship between the times that a part is in each location of the furnace, the temperature of the

part as it travels through the furnace and the atmosphere seen by the part during each stage of the

sintering process.

[28]

1.4 EGG SHELL

Calcium carbonate is a chemical compound with the formula CaCO3. It is formed by three

main elements: carbon, oxygen and calcium. It is a common substance found in rocks in all parts

of the world, and is the main component of shells of marine organisms, snails, coal, pearls,

and eggshells. Calcium carbonate is the active ingredient in agricultural field, and is created when

Ca ions in hard water react with carbonate ions creating lime scale. It is commonly used

medicinally as a calcium supplement or as an antacid, but excessive consumption can be

hazardous.

Figure 1.4.1; EGG SHELL POWDER

[29]

Chemistry

● it reacts with strong acids, releasing carbon dioxide:

CaCO3(s) + 2 HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)

● it releases carbon dioxide on heating, called a thermal decomposition reaction,

or calcination, (to above 840 °C in the case of CaCO3), to form calcium oxide, commonly

called quicklime, with reaction enthalpy 178 kJ / mole:

CaCO3(s) → CaO(s) + CO2(g)

Calcium carbonate will react with water that is saturated with carbon dioxide to form

the soluble calcium bicarbonate.

CaCO3 + CO2 + H2O → Ca(HCO3)2

Structure

The thermodynamically stable form of CaCO3 under normal conditions is hexagonal β-

CaCO3, (the mineral calcite). Other forms can be prepared, the denser, (2.83 g/cc) orthorhombic

λ-CaCO3 (the mineral aragonite) and μ-CaCO3, occurring as the mineral vaterite. The aragonite

form can be prepared by precipitation at temperatures above 85 °C, the variety form can be

prepared by precipitation at 60 °C. Calcite contains calcium atoms coordinated by 6 oxygen atoms,

in aragonite they are coordinated by 9 oxygen atoms. The vaterite structure is not fully understood.

[30]

Occurrence

Geological sources

Calcite, aragonite and vaterite are pure calcium carbonate minerals. Industrially important

source rocks which are predominantly calcium carbonate

include limestone, chalk, marble and travertine.

Biological sources

Eggshells, snail shells and most seashells are predominantly calcium carbonate and can be

used as industrial sources of that chemical. Oyster shells have enjoyed recent recognition as a

source of dietary calcium, but are also a practical industrial source. While not practical as an

industrial source, dark green vegetables such as broccoli and kale contain dietary significant

amounts of calcium carbonate.

Extra terrestrial

Beyond Earth, there is strong evidence that Calcium carbonate was detected on the

planet Mars at more than one location, providing evidence for the past presence of liquid water.

Uses

Industrial applications

The main use of calcium carbonate is in the construction industry, either as a building

material or limestone aggregate for road building or as an ingredient of cement.

Calcium carbonate is also used in the purification of iron from iron ore in a blast

furnace

[31]

●In the oil industry, calcium carbonate is added to drilling fluids as a formation-bridging

and filter cake-sealing agent.

It is also used as a raw material in the refining of sugar from sugar beet.

Calcium carbonate has traditionally been a major component of blackboard chalk.

Calcium carbonate is widely used as an extender in paints in particular matte emulsion

paint.

In ceramics/glazing applications, calcium carbonate is known as whiting and is a

common ingredient for many glazes in its white powdered form.

Health and dietary applications

●Calcium carbonate is widely used medicinally as an inexpensive dietary calcium

supplement or gastric antacid.

●Calcium carbonate is used in the production of toothpaste and has seen resurgence as a

food preservative and colour retainer, when used in or with products such as organic apples or

food.

.

.

[32]

Calcination equilibrium

Calcination of limestone using charcoal fires to produce quicklime has been practiced

since antiquity by cultures all over the world. The temperature at which limestone yields calcium

oxide is usually given as 825 °C, but stating an absolute threshold is misleading. Calcium

carbonate exists in equilibrium with calcium oxide and carbon dioxide at any temperature. At

each temperature there is a partial pressure of carbon dioxide that is in equilibrium with calcium

carbonate. At room temperature the equilibrium overwhelmingly favours calcium carbonate,

because the equilibrium CO2 pressure is only a tiny fraction of the partial CO2 pressure in air,

which is about 0.035 kPa.

At temperatures above 550 °C the equilibrium CO2 pressure begins to exceed the

CO2 pressure in air. So above 550 °C, calcium carbonate begins to outgas CO2 into air. However,

in a charcoal fired kiln, the concentration of CO2 will be much higher than it is in air. Indeed if all

the oxygen in the kiln is consumed in the fire, then the partial pressure of CO2 in the kiln can be

as high as 20 kPa.

[33]

CHAPTER 2

EXPERIMENTAL PROCEDURE

Here, through this project we aim on the dielectric properties of ceramic materials for this

we had chosen a biological ceramic sample that is the eggshell as the sample for our project.

2.1 SELECTION OF SAMPLE AND POWDER FORMING

Our guide had given this sample to us in a half grinded state and gives us the instructions.

The first step is to change the half grinded state of the sample into fine powder. For this we used

agate, pistil and a spatula. After cleaning agate, pistil, and spatula using cotton and acetone, we

put this half grinded sample into the agate and started grinding using pistil. About 9-10 hours of

time had taken to obtain the fine powder of the sample. Using spatula we had check the fineness

of the sample. Our guide had confirmed the fineness of the sample. After that we had started the

other process for preparing a dielectric.

2.2 CALCINATION

Calcination is the first process that we had done. It is a thermal treatment process to bring

about a thermal decomposition. This process takes place below the melting point of the product.

Melting point of our sample is about 8250C obtained from the theoretical data’s. First of all, we

had taken a test sample. That is put in a crucible and placed in a muffle furnace to heat it of about

4000C. But at 4000C, successful calcination was not occurring. So we had changed the temperature

to 5000C from 4000C. At that temperature successful calcination had occurrence.

[34]

2.3 FORMING

After calcination, the sample is again put it in the agate for grinding to become in fine

powder. Polyvinyl alcohol (PVA) was added into the powder and mixed it very well. After that,

this sample is placed inside a Hot air oven for the heating process at a temperature of about 1000C.

On the next day, this sample was taken out from the oven. We observed that this powder become

sticky on the surface of the agate. Using spatula we removed the powder from the surface of the

agate and again grinded using pistil. The next process was pelletizing.

2.4 PELLETIZATION

Hydraulic press is the instrument that is used for pelletizing. We had selected a medium

sized dice. After that using cotton and acetone we had cleaned up the dice. Using spatula we had

selected small amount of powder and put it in inside the dice. Then it is adjusted to a particular

height and placed in the hydraulic press. The pressure is then made tight. By using a liver in the

hydraulic press, pressure is applied into the dice. A pellet of about 46GPa is prepared first. Like

this different sized pellets are made at 54GPa and 60GPa. The last step for the dielectric

preparation was sintering.

2.5 SINTERING

It is a technology that helps to broaden the applications and to improve the overall quality

and competitiveness of powder metal components. For this, the test sample of pellet is placed

inside the Muffle furnace and adjusted the temperature to 7000C. After sintering we wait for about

one day to take the pellet out from the muffle furnace. But when the pellet becomes cool, it is

observed that the pellet had broken and changed to powder state. The actual melting point of

CaCO3 is 8250C. But from the observation it is clear that, on a temperature of 7000C the pellet

[35]

had broken, so if 8250C is applied without any doubt it is clear that it can’t exist as a pellet. So we

had continued our project with the powdered form of CaCO3 after sintering.

2.6 MEASUREMENTS

The measurement was done by using the instrument LCR High tester. With this instrument,

different measurements can be taken. Here we measured the parallel capacitance, parallel

resistance, parallel inductance, series capacitance, series resistance, series inductance and Q- factor

of our sample powder. Two silver capacitor plates is used to place this dielectric.

Steps

● First the LCR high tester is adjusted in open circuit.

● Next is the short circuiting of the LCR high tester.

● Then the capacitor plate is connected into the LCR high tester by using a connecting wire.

Measurements are taken at different frequencies and we obtained the characteristics of CaCO3

from our limited data’s.

[36]

CHAPTER 3

RESULTS AND DISCUSSIONS

This portion includes the various measurements such as the capacitance, resistance, inductance

and Q-factor of the sample that is used for our project according to changes in the applied

frequencies. Graphs of these measurements are plotted against the applied frequencies. Each

measurements are tabulated separately and also its graphs. From this graph we can analyze the

variations of the quantities corresponding to the increase and decrease of frequencies and these

variations are clearly observable from the graph. This includes,

● PARALLEL CAPACITANCE v/s FREQUENCY

●SERIES CAPACITANCE v/S FREQUENCY

●PARALLEL RESISTANCE v/s FREQUENCY

●SERIES RESISTANCE v/s FREQUENCY

●PARALLEL INDUCTANCE v/s FREQUENCY

●SERIES INDUCAENCE v/s FREQUENCY

●Q-FACTOR v/s FREQUENCY

[37]

3.1 PARALLEL CAPACITANCE v/s FREQUENCY

Table 3.1.1

FREQUENC

Y(KHz)

Cp(

PF)

0.05

442.

6

0.1

339.

8

0.2

258.

6

0.3

218.

8

0.5

177.

6

1

125.

4

2 83.9

3 67.4

4 57.2

5 51.2

6 46.2

7 42.6

8

39.7

7

9 37.2

10 35.2

20 24.9

50 16.7

1000 7.97

2000 7.5

3000 7.2

4000 7.2

5000 7.08

Frequency(KHz)

Figure3.1.1

[38]

SERIES CAPACITANCEv/s FREQUENCY

[39]

Table3.2.1

FREQUENCY(KHz) Cs(PF)

0.05 34900

0.1 15800

0.2 6200

0.3 4009

0.5 2480

1 1197

2 622.8

3 438.2

4 350.9

5 290.5

6 250.1

7 219.9

8 198.2

9 179.1

10 164.7

20 89.8

50 42.2

1000 8.4

2000 7.74

3000 7.39

4000 7.4

5000 7.1

[40]

Figure3.2.1

3.3 PARALLEL RESISTANCE v/s FREQUENCY

Table3.3.1

[41]

FREQUENCY(KHz) Rp(Kᾨ)

0.05 814.2

0.1 696.4

0.2 638.5

0.3 543.4

0.5 492.2

1 434.2

2 372.2

3 335.2

4 307.5

5 287.9

6 272.96

7 262.5

8 251.9

9 243.4

10 235.4

20 197.7

50 153.7

1000 82.9

[42]

2000 59.7

3000 52.3

4000 40.5

5000 36.5

Figure3.3.1

3.4 SERIES RESISTANCE v/s FREQUENCY

Table3.4.1

FREQUENCYK(Hz) Rs(Kᾨ)

0.05 796.42

0.1 694.7

0.2 604.7

0.3 555.6

0.5 459.2

1 389.3

2 323.9

3 284.7

4 255.6

5 237.9

6 222.2

7 211.7

8 200.7

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9 192.8

10 184.7

20 143.4

50 92.6

1000 4.6

2000 1.8

3000 1

4000 0.7263

5000 0.5362

Figure3.4.1

[44]

3.5 PARALLEL INDUCTANCE v/s FREQUENCY

Table3.5.1

FREQUENCY(KHz) Lp(H)

0.05 22700

0.1 7440

0.2 2430

0.3 1280

0.5 560.8

1 202.09

2 75.14

3 4.72

4 27.73

5 19.75

6 15.21

7 12.16

8 9.95

9 8.38

10 7.174

20 2.54

50 0.6088

1000 0.00316

2000 0.843

3000 0.0003883

4000 0.0002172

5000 0.0001429

[45]

Figure3.5.1

3.6 SERIES INDUCTANCE v/s FREQUENCY

Table3.6.1

FREQUENCY(KHz) Ls(H)

0.05 291.5

0.1 158.2

0.2 101.8

0.3 69.4

0.4 40.8

1 21.1

2 10.2

3 6.3

4 4.6

[46]

5 3.45

6 2.8

7 2.34

8 1.99

9 1.74

10 1.54

20 0.6974

50 0.2398

1000 3.01E-07

2000 0.0008178

3000 0.0003818

4000 0.0002135

5000 0.0001407

Figure3.6.1

[47]

3.7 Q-FACTOR v/s FREQUENCY

Table3.7.1

FREQUENCY(KHz) Q

0.05 0.11

0.1 0.15

0.2 0.21

0.3 0.24

0.5 0.28

1 0.34

2 0.4

3 0.42

4 0.44

5 0.46

6 0.48

7 0.49

8 0.5

9 0.51

10 0.52

20 0.62

50 0.81

1000 4.1

2000 5.58

3000 7.1

4000 7.5

5000 8.3

[48]

Figure3.7.1

CONCLUSION

[49]

The various measurements are tabulated and its graphs are plotted. The graph

is analyzed and observed the variations in capacitance, resistance, inductance and Q-

factor with the increase in the applied frequencies of the dielectric prepared by our

project. This project basically deals with the dielectric properties of ceramic material

that has been used by us. Our sample has shown less cohesive force, so that it can’t

remain in solid or in a pelletized form. So here we used the powdered form to

measure the dielectric properties. Parallel capacitance, series capacitance, parallel

resistance, series resistance, parallel inductance and series inductance decreases with

increase in the frequency. Only the Q-factor increases with increase in frequency.

This shows the different dielectric properties of our sample.

REFERENCE

● Ceramic Processing and Sintering- M.N. RAHAMAN

●Advances in Powder Metal Sintering Technology- Stephen L. Feldbauer

[50]

●http://www.pslc.ws/macrog/iblend.htm

●http://www.sekisui-sc.com/applications/index.html

●http://www.tpub.com/content/medical/14274/css/14274_146.htm

●www.metalformingfacts.com

●www.wikipedia.com

●www.google.com

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