byeong-joo lee calphad computational thermodynamics byeong-joo lee computational materials science...

Byeong-Joo Lee www.postech.ac.kr/~calphad

Computational Computational ThermodynamicsThermodynamics

Byeong-Joo Lee Byeong-Joo Lee

Computational Materials Science & Engineering Lab.Computational Materials Science & Engineering Lab.Pohang University of Science & TechnologyPohang University of Science & Technology


R&D in Materials Science and EngineeringR&D in Materials Science and Engineering

Structure Structure EvolutionEvolution

Process Process ConditionCondition

Materials Materials PropertyProperty

Research Type I : experiments first, then thinkingResearch Type II: think first, then do experiments


Lattice StabilityLattice Stability

VPSTHG


BABABBAA

Bo

BAo

Am

LxxxxxxRT

GxGxG

,)lnln(

ABABBBBBAAAABA EWEWEWE

221

AAA NzxW 221

BBB NzxW

BAAB xNzxW

])2[(2 BBAAABBABBBAAABA EEExxExExNz

E

Regular Solution vs. Quasi-Chemical ModelRegular Solution vs. Quasi-Chemical Model


Thermodynamic Assessment Thermodynamic Assessment – Cr-Ni Binary System– Cr-Ni Binary System

NiCrNiCrNiNiCrCrNio

NiCro

Crm LyyyyyyRTGyGyG ,)lnln(

B.-J. Lee, 1992B.-J. Lee, 1992

LLfccfccCr,Ni Cr,Ni = 8030 – 12.8801·T + (33080 – 16.0362·T)(1-2X = 8030 – 12.8801·T + (33080 – 16.0362·T)(1-2XNiNi))

LLbccbccCr,NiCr,Ni = 17170 – 11.8199·T + (34418 – 11.8577·T)(1-2X = 17170 – 11.8199·T + (34418 – 11.8577·T)(1-2XNiNi))

LLliqliqCr,NiCr,Ni = 318 – 7.3318·T + (16941 – 6.3696·T)(1-2X = 318 – 7.3318·T + (16941 – 6.3696·T)(1-2XNiNi))


Thermodynamic Calculation – Fe-Cr-Ni Ternary SystemThermodynamic Calculation – Fe-Cr-Ni Ternary System


Thermodynamic Parameters (Fe,Cr,Mo)(Va,B,C,N)Thermodynamic Parameters (Fe,Cr,Mo)(Va,B,C,N)

VaMoo

VaMoVaCro

VaCrVaFeo

VaFem GyyGyyGyyG ::: BMoo

BMoBCro

BCrBFeo

BFe GyyGyyGyy :::

CMoo

CMoCCro

CCrCFeo

CFe GyyGyyGyy ::: NMoo

NMoNCro

NCrNFeo

NFe GyyGyyGyy :::

)lnlnln( MoMoCrCrFeFe yyyyyyaRT )lnlnlnln( NNCCBBVaVa yyyyyyyycRT

xsmo GG

VaMoCrVaMoCrVaMoFeVaMoFeVaCrFeVaCrFexs LyyyLyyyLyyyG :,:,:, BVaMoBVaMoBVaCrBVaCrBVaFeBVaFe LyyyLyyyLyyy ,:,:,:

CVaMoCVaMoCVaCrCVaCrCVaFeCVaFe LyyyLyyyLyyy ,:,:,: NVaMoCVaMoNVaCrCVaCrNVaFeNVaFe LyyyLyyyLyyy ,:,:,:

BMoCrBMoCrBMoFeBMoFeBCrFeBCrFe LyyyLyyyLyyy :,:,:, CMoCrCMoCrCMoFeCMoFeCCrFeCCrFe LyyyLyyyLyyy :,:,:,

NMoCrCMoCrNMoFeCMoFeNCrFeNCrFe LyyyLyyyLyyy :,:,:, CBMoCBMoCBCrCBCrCBFeCBFe LyyyLyyyLyyy ,:,:,:

NBMoNBMoNBCrCBCrNBFeNBFe LyyyLyyyLyyy ,:,:,: NCMoNCMoNCCrNCCrNCFeNCFe LyyyLyyyLyyy ,:,:,:

VaMoCrFeVaMoCrFe Lyyyy :,,


Thermodynamic Calculation – Practical SteelsThermodynamic Calculation – Practical Steels


Thermodynamic Calculation – Application to Alloy DesignThermodynamic Calculation – Application to Alloy Design

Computational Thermodynamics 의 적용 분야 Structural Materials (Steel, Solder, Al-, Ti-, Ni-, Mg-alloys), Semiconducting Materials, Ceramic Materials, Hydrogen Storage Materials, CVD process 등 열역학이 지배하는 모든 물질계


AB1: 0.1C-5MN-7Al AB2: 0.2C-4Mn-6.6Al AB3: 0.3C-3.5Mn-6Al AB4: 0.4C-3.5Mn-5.8Al

AB5: 0.5C-3Mn-4.9Al AB6: 0.3C-4Mn-7.3Al-0.05Ti

Thermodynamic Calculation – Application to Alloy/Process DesignThermodynamic Calculation – Application to Alloy/Process Design


Thermodynamics Assessment - Na-Al-H system


Assessment of thermodynamic properties in the Li-Al-H ternary systemAssessment of thermodynamic properties in the Li-Al-H ternary system


※ Example: Deposition of Silicon SiH4 + 2Cl2 = Si + 4HCl

Driving force of CVD Deposition Driving force of CVD Deposition


Interfacial ReactionsInterfacial Reactions


Interfacial Reaction between Cu and Various Solder

-Experimental Observation

▶ Cu/Sn : Cu6Sn5 ▶ Cu/Sn-Pb eutectic : Cu6Sn5 ▶ Cu/Sn-Ag eutectic : Cu6Sn5 ▶ Cu/Sn-Zn eutectic : CuZn_γ ▶ Cu/Sn-In eutectic : Cu2(Sn,In) or Cu2In3Sn


Application to Solder/Substrate Interfacial Reactions Application to Solder/Substrate Interfacial Reactions – Cu/Sn – Cu/Sn ReactionReaction


Application to Thin Film Reactions Application to Thin Film Reactions – Metal/Si Reaction– Metal/Si Reaction


Application to Thin Film Reactions Application to Thin Film Reactions – Metal/Si Reaction– Metal/Si ReactionSi Sample Preparation Heat Treatment Measurement Amorphous First Silicide ref.

crystal(111)

triode d.c. sputteringbilayer (Ti: 95,400nm)

isothermal(30min at 500oC)

XRD/TEM - Ti5Si3 & TiSi 50

crystal(111)

electron-gun depositionbilayer (Ti: 300nm)

isothermal120min at 500oC

RBS - aTiSi & TiSi251

polycrystal magnetron S-gun sputteringbilayer (Ti: 100nm)


XRD - TiSi & TiSi252

crystal<100>

evaporationbilayer (Ti:100nm)


RBS/XRD - TiSi & TiSi253

amorphousor <100>

electron-gun depositionbilayer (Ti: 90nm)


BackscatteringSpectroscopy

- TiSi 54

crystal(111)

electron-beam evaporationbilayer (Ti: 3nm)


TEM - TiSi & TiSi255

crystal(100)

conventional HV sputteringbilayer (Ti: 30nm)


RBS/TEM - TiSi2 (C49) 56

crystal<100>

electron-gun evaporationbilayer (Ti: 140nm)


RBS/XRD/TEM - bTiSi257

amorphous electron-beam evaporationtrilayer (Ti: 10~100nm)

isothermal(~300s at 560oC)

TEM yesSSA Ti5Si3

45

amorphousor <100>

sputter-depositiona-Si/Ti/Si trilayer (Ti: 23nm)


TEM/RBS yesSSA TiSi2 (C49) 58

crystal(100)

sputter depositionbilayer (Ti: 25~35nm)


HRTEM/EDS yesSSA TiSi2 (C49) 59

crystal(111)

UHV e-beam evaporationa-Si/Ti/Si trilayer (Ti: 30nm)


in-situ RHEED/HRTEM

yesSSA

cTi5Si360

poly Si rf sputteringbilayer (Ti: 55nm)

heating (10oC/m)to 510oC

XTEM/STEM yesSSA TiSi2 (C49) 61

crystal(100)

magnetron sputteringbilayer (Ti: 32,51nm)

heating (15oC/min)to approx. 800oC

IR-abs spect.XRD/resistivity

yesSSA TiSi2 (C49) 62

crystal(100)

magnetron sputteringbilayer (Ti: 32,46nm)

heating (3,20oC/s)to approx. 800oC

in-situ XRD - Ti5Si3/Ti5Si463


Application to Thin Film Reactions Application to Thin Film Reactions – Metal/Si Reaction– Metal/Si Reaction


Application to Interfacial Reactions Application to Interfacial Reactions – Metal/Si Reaction– Metal/Si Reaction


Application to Metal/Ceramics Interfacial Reactions Application to Metal/Ceramics Interfacial Reactions – Ti/Al– Ti/Al22OO33

ReactionReaction


Computational Materials Science & Engineering Lab.Computational Materials Science & Engineering Lab.Pohang University of Science & Technology, KoreaPohang University of Science & Technology, Korea

Eunha KimEunha Kim

Inyoung SaInyoung Sa

Byeong-Moon LeeByeong-Moon Lee

andand

Byeong-Joo Lee Byeong-Joo Lee

Thermodynamics Nano MaterialsThermodynamics Nano Materials


Size Effect on the Melting Point Size Effect on the Melting Point for Au nano particles & wiresfor Au nano particles & wires


VLS Growth of Nanowires VLS Growth of Nanowires - GeSi Nanowires - GeSi Nanowires


②

①

① Vapor-Liquid

② Liquid-Solid

SiH4 + GeH4 + H2

0.0 0.2 0.4 0.6 0.8 1.00

50

100

150

200

250

Act

ivit

y o

f S

i

X(Si)

Au-Si liquid solution, T=673K, P=200Torr

(a)

Reactions during the VLS Process


②

①

① Vapor-Liquid

② Liquid-Solid

①

②

SiH4 + GeH4 + H2

0.0 0.2 0.4 0.6 0.8 1.00

50

100

150

200

250

Act

ivit

y o

f S

i

X(Si)

Au-Si liquid solution, T=673K, P=200Torr

(a)

Reactions during the VLS Process

200 torr

400 oC


Size dependence of SiGe nanowire compositionSize dependence of SiGe nanowire composition

0.00 0.25 0.50 0.75 1.000.00

0.25

0.50

0.75

1.000.00

0.25

0.50

0.75

1.00

Liquid (Bulk) Solid (Bulk) Liquid (D=10nm) Solid (D=10nm)

FCC+LDIAMOND+L

SiAu

Ge

0.0 0.2 0.4 0.6 0.8 1.0

Gib

bs

Ener

gy

of Form

atio

n

Bulk liquid

XSi or XGe

Nanosized liquid

Capillarity Effect

Si or Ge

0.0 0.2 0.4 0.6 0.8 1.0-10

0

10

20

30

Au-Ge liquid

Gib

bs

En

erg

y o

f F

orm

ati

on

,k

J/g

ram

ato

m

XSi or XGe

Au-Si liquid


Size dependence of SiGe nanowire compositionSize dependence of SiGe nanowire composition

0 30 60 90 120 15065

70

75

80

85

XAu=0.20, XSi=0.20, XGe=0.60

XAu=0.40, XSi=0.15, XGe=0.45

XAu=0.60. XSi=0.10, XGe=0.30

Ge

con

ten

t, a

t%

Diameter, nm

0 30 60 90 120 15035

40

45

50

55

XAu

=0.20, XSi=0.40, XGe

=0.40

XAu

=0.40, XSi=0.30, XGe

=0.30

XAu

=0.60, XSi=0.20, XGe

=0.20

Ge

con

ten

t, a

t%

Diameter, nm

0 30 60 90 120 1505

10

15

20

25

XAu=0.20, XSi=0.60, XGe=0.20

XAu=0.40, XSi=0.45, XGe=0.15

XAu=0.60, XSi=0.10, XGe=0.30

Ge

con

ten

t, a

t%

Diameter, nm

CALPHAD (2008)CALPHAD (2008)


SummarySummary

Computational Thermodynamics

• Calculation of Multi-component Phase DiagramsCalculation of Multi-component Phase Diagrams • Interfacial Reactions Interfacial Reactions – – Metal/Liquid Solder, Metal/CeramicsMetal/Liquid Solder, Metal/Ceramics• Thin Films ReactionsThin Films Reactions – – Metal/SiliconMetal/Silicon• Thermodynamics of Nano MaterialsThermodynamics of Nano Materials – – Capillarity Effect Capillarity Effect

byeong-joo lee calphad computational thermodynamics byeong-joo lee computational materials science...

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