step-by-step powder composite mechanosynthesis for
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Journal of Physics Conference Series
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Step-by-step powder compositemechanosynthesis for functional nanoceramicsTo cite this article A O Polyakov et al 2010 J Phys Conf Ser 217 012081
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Step-by-step powder composite mechanosynthesis for
functional nanoceramics
A O Polyakov1 T Yu Kiseleva
1 A A Novakova
1 T F Grigoryeva
2 and
A P Barinova2
1Moscow MVLomonosov State University Department of Physics Vorobrsquoevy Gory
Russia 2Institute of solid state chemistry and mechanochemistry SO RAS Novosibirsk
Kutateladze st
E-mail alexpolmsugmailcom
To study the possibility of Fe2O3 mechanochemical reduction by preliminary mechanically
alloyed Fe+20Al compound their powder mixture was subjected to high-energy ball-milling
in Ar atmosphere with the milling time varying between 2 and 12 minutes The milled samples
obtained at various times of milling were characterized by X-ray diffraction and Moumlssbauer
spectroscopy As a result gradual α-Fe2O3 reduction via formation of intermediate Fe-Al-O
oxides was observed The presence of the intermediate Fe2AlO4 spinel phases stable over long
milling time is stated Mechanocomposite Fe+20Al transformation to α-Fe(Al) solid
solutions which evolve peculiarly with the milling time was observed also The kinetics of α-
Fe2O3 reduction process was analyzed in comparison with the same processes in the systems
α-Fe2O3 + Al and α-Fe2O3 + Al + Fe
1 Introduction
The possibility of taking the advantage of particular properties of the constituent materials to meet
specific demands is the most important motivation for the development of composites In this way we
are working on varying the mechanosynthesised composites final structure for different purposes
Recently we have studied the processes of Al2O3Fe-Al [1] Fe2O3Fe3O4Fe [2] nanocomposites
mechanochemical formations The thermite solid state reduction reaction of α-Fe2O3 with metallic
reductant (Al Fe) was realized in those processes α-Fe2O was consistently reduced to Fe through
intermediate binary and ternary oxides Reduced Fe subsequent alloying with reductant surplus
resulted in Al2O3intermetallic phases composites formation The metal-reductant surplus in the
mixture leads to deceleration of Fe2O3 reduction and incapsulated structures formation Fe as
additional reductant caused some shift of the activation barrier of Fe2O3 reduction The ordering-
disordering phenomena led to amorphous iron-based magnetic phase formation in grain-boundary
regions This phase is stable for a long milling time and after heating up to 500oC [2] Its formation
creates the additional competitive process to Fe2O3 destruction To study the possibility of Fe2O3
mechanochemical reduction alloyed Fe-Al intermetallic compounds in high energy planetary ball mill
activation of pre-milled Fe+20Al mixture with Fe2O3 have been performed
2 Experimental
Ball milling of 8 g Fe powder with 2 g of Al powder was performed in AGO-2 planetary ball mill for
20 minutes in a vial sealed under Ar Then 3 g of α- Fe2O3 powder was added into 5 g of pre-milled
Fe-Al mixture and again subjected to 2 6 and 12 minute ball milling Vial volume was 250 cm3 Balls
diameter and mass were 5 mm and 200 g respectively The speed of drums rotation was ~1000 rpm
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
ccopy 2010 IOP Publishing Ltd 1
The 57
Fe Moumlssbauer spectra (MS) were recorded at room temperature with 57
Co(Rh) X-ray diffraction
(XRD) of as-milled and annealed powder samples was performed at Rigaku DXMax diffractometer
with Cu Kα radiation
3 Results and discussion X-ray diffraction image of Fe+20Al powder mixture milled for 20 min is shown in Fig1 (a) The
broadened peaks with maxima at the angles of FeAl may correspond not only to disordered (or even
amorphous) FeAl phase and its solid solution but also to structural reflections of FeAl2 and Fe2Al5
intermetallics also The presence of well resolved narrow Al peaks on the diffraction pattern indicate
unreacted Al
Moumlssbauer (Fig 2a) analysis of pre-milled Fe+20Al presented in bar diagram shows that
after 20 min of milling interaction between Fe and Al leads to the formation of highly disordered
composite consisted of FeAl Fe2Al5 and FeAl2 intermetallic phases and disordered Fe(Al) solid
solution We observed isomer shifts and quadrupole splittings change to some extent increased
linewidths of subspectra and even additional subspectra appearence in the case of FeAl phase As was
observed [4] FeAl disordering leads to the magnetically split component being resolved in addition to
the non-magnetic singlet Thus after 20 minutes of high energy ball milling of Fe+20Al we obtain
intermetallic phase composite
Figure 1 XRD pattern for 20 minutes ball milling Fe+20Al (a) mechanoactivated Fe+20Al
composite and Fe2O3 simply mixed (b) and mechanoactivated during 2(c) 6(d) and 12(e)
minutes
2 0 4 0 6 0 8 0 1 0 0
0
1 0 0 0
2 0 0 0
3 0 0 0
e )
d )
c )
b )
a )
Int
Int
Int
Fe
(20
0)
Fe
Al(
20
0)
Fe
Al(
20
0)
FeA
l(1
00)
Fe
(22
0)
Fe
Al(
21
1)
Fe(2
00
)
Fe(2
20
)
2 Θ
2 0 4 0 6 0 8 0 1 0 0
0
1 0 0 0
2 0 0 0
3 0 0 0
FeA
l(200)
Fe
Al(
200
)
Fe
2O
3(1
13
)
Fe
(11
0)
Fe
Al(
110
)
Fe3
O4
(44
0)
Fe
Al(
10
0)
Fe3
O4
(31
1)
Fe
(110
)F
eA
l(11
0)
Fe
(20
0)
Fe
Al(
211
)
Fe
(22
0)
2 0 4 0 6 0 8 0 1 0 0
0
5 0 0
1 0 0 0
1 5 0 0
2 0 0 0
Fe(2
20)
Fe2
O3(1
0 1
0)
Fe(2
20)
Fe
Al(2
11
)
Fe
3O
4(4
40
)
Fe
3O
4(3
11
)
Fe
2O
3(3
00
)
Fe
2O
3(2
14
)
Fe2O
3(1
16)
Fe2
O3
(02
4)
Fe2O
3(1
13)
Fe2O
3(1
10)
Fe2O
3(1
04)
FeA
l(10
0)
Fe2O
3(0
12
)
2 0 4 0 6 0 8 0 1 0 0
0
5 0 0
1 0 0 0
1 5 0 0
Fe
Al 2
(11
0)
Fe
(220
)
Fe
Al(2
11)
FeA
l(10
0)
Fe
Al(
110
)
Fe
2O
3(2
20
)
Fe2O
3(2
26)
Fe2O
3(2
1 1
0)
Fe2O
3(1
0 1
0)
Fe
(22
0)
Fe(2
20)
Fe
Al(2
11)
Fe
(200
)
Fe2O
3(0
18)
Fe(1
10)
FeA
l(110)
Fe
(110
)F
eA
l(11
0)
Fe2O
3(3
00)
Fe2O
3(2
14)
Fe
2O
3(0
18
)
Fe2
O3(1
16)
Fe
2O
3(0
24
)
Fe2O
3(1
13)
Fe
2O
3(1
10
)
Fe2
O3
(10
4)
Fe2
O3(0
12)
2 0 4 0 6 0 8 0 1 0 0
0
4 0 0 0
8 0 0 0
1 2 0 0 0
Fe
Al(
20
0)
Fe
Al(
211
)A
l(22
2)
Al(
11
1)
Fe
Al(1
00)
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
2
The XRD pattern (Fig 1b) and Moumlssbauer spectrum (Fig 2b) of simple mixture Fe2O3 and pre-
activated Fe-Al composite correspond to mixed components contributions in the ratio 12 The percent
of intermetallics component is about 60 that indicate metallic component prevalence
As is seen from XRD pictures (Fig 1 cde) the subsequent milling of this mixture results in
phase transformations arising from the Fe2O3 and Fe-Al composite interaction Fe2O3 destruction after
2 min is reflected in its intensity decrease and structure peaks widening is observed The main wide
composite intermetallic peak becomes narrow Al peaks disappeared fully According to Moumlssbauer
data (Fig 2c) the mixture after 2 min contains Fe2O3 Fe3O4 Fe and 42 of a disordered
intermetallics mixture Milling for 6 min (Fig 1 d Fig 2) reveals Fe2O3 peaks disappearance on XRD
pattern and wide Fe3O4 maxima rise Moumlssbauer data confirm that the mixture is composed of Fe2O3
Fe3O4 and disordered intermetallics mixture It is interesting that at this time of milling traces of
ternary compound FeAl2O4 were detected Finally after 12 min (Fig 1 e) the XRD pattern consists of
only wide and asymmetric maxima which reflect the bcc α-Fe(Al) solid solution formation Moumlssbauer
spectrum (Fig 2) analysis reveal not only α-Fe(Al) formation but also disordered intermetallics and
ternary oxide Generally analyzing Moumlssbauer data of different milling time gradually Al rich
intermetallic phases decrease in accordance with hematite reduction and bcc α-Fe(Al) solid solution
Figure 2 Moumlssbauer spectra and phase diagrams of pre-milled Fe+20Al (a) pre-milled
Fe+20Al simply mixed with Fe2O3(b) mechanoactivated during 2(c) 6(d) and 12(e) minutes
-10 -5 0 5 10090
092
094
096
098
100
S
0
20
40
60
80
100
b)
a )
Fe
Al 2
Fe
3O
4
Fe
Fe
Fe
Al 2
dis
ord
Fe
Al
Fe
Al 2
Fe
2A
l 5
-10 -5 0 5 10090
092
094
096
098
100
S
e)
d )
c)0
20
40
60
80
100
dis
ord
Fe
2A
l 5
Fe
2O
3
Fe(A
l)
FeA
l
Fe
2O
3F
e2O
3
-10 -5 0 5 10090
092
094
096
098
100
102
S
0
20
40
60
80
100
Fe
2A
l 5
dis
ord
Fe
3O
4
Fe
(Al)
Fe
(Al)
Fe
Al
-10 -5 0 5 10
090
092
094
096
098
100
S
V m m s
0
20
40
60
80
100
Fe
Al 2O
4
dis
ord
Fe
Al 2
O4
FeA
l
-10 -5 0 5 10
088
092
096
100
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
0
20
40
60
80
100
S
Fe
Al 2
Fe
Al
dis
ord
Fe
2A
l 5
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
3
formation is clearly detected It should be noted that no oxide phases of aluminum were detected on
XRD pattern which is assumed due to possible X-ray amorphous modification of it Evaluation of
aluminum concentration in a-Fe(Al) solid solution was performed by analysis of hyperfine fields
distribution of the corresponding Moumlssbauer spectrum component (Fig 2 (e)) and reveals the value 7
at
Figure 3 The fraction of Fe2O3 depending on
milling time t in (a) the system under study (b) in
comparison with analogous systems α-Fe2O3 + Al
and (c) α-Fe2O3 + Al + Fe
Fig 3 demonstrates the kinetics of Fe2O3 destruction in different powder mixture with equal surplus of
metal reductant component subjected to high energy ball milling Amorphous phase formation in the
presence of iron compounds leads to the slowing down the oxide reduction process
4 Conclusions
Moumlssbauer spectroscopy and X-ray diffraction study of subsequent interaction of α-Fe2O3 with pre-
mechanoactivated Fe+20Al composite powder mixture reveal gradual α-Fe2O3 reduction via
formation of iron binary and ternary oxides up to Fe On the other hand Fe-Al mechanocomposite
transformations lead to disordered α-Fe(Al) solid solution and Fe-based amorphous phase formation
Complete amorphous phase formation on the iron surface decreases its reductant ability and slows
down the process of α-Fe2O3 reduction in comparison with the analogous systems
References
[1] AANovakova TYuKiseleva et al 14th IntSymp on Metastable and Nano-MaterISMANAM-
2007 Corfu Greece Proceed 179 (2007)
[2] TYuKiseleva AANovakova MIChystyakova AOPolyakov et al Solid State Phenomena
152-153 25-28 (2009)
[3] TYuKiseleva AANovakova TFGrigorieva et al Advanced materials 6 1-10 (2008)
[4] SGialanella XAmils et al Acta mater 46 3305 (1998)
0 100 200 300 400 500 600 700 800
0
20
40
60
80
100
c b
F
e2
O3
t sec
a
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
4
Step-by-step powder composite mechanosynthesis for
functional nanoceramics
A O Polyakov1 T Yu Kiseleva
1 A A Novakova
1 T F Grigoryeva
2 and
A P Barinova2
1Moscow MVLomonosov State University Department of Physics Vorobrsquoevy Gory
Russia 2Institute of solid state chemistry and mechanochemistry SO RAS Novosibirsk
Kutateladze st
E-mail alexpolmsugmailcom
To study the possibility of Fe2O3 mechanochemical reduction by preliminary mechanically
alloyed Fe+20Al compound their powder mixture was subjected to high-energy ball-milling
in Ar atmosphere with the milling time varying between 2 and 12 minutes The milled samples
obtained at various times of milling were characterized by X-ray diffraction and Moumlssbauer
spectroscopy As a result gradual α-Fe2O3 reduction via formation of intermediate Fe-Al-O
oxides was observed The presence of the intermediate Fe2AlO4 spinel phases stable over long
milling time is stated Mechanocomposite Fe+20Al transformation to α-Fe(Al) solid
solutions which evolve peculiarly with the milling time was observed also The kinetics of α-
Fe2O3 reduction process was analyzed in comparison with the same processes in the systems
α-Fe2O3 + Al and α-Fe2O3 + Al + Fe
1 Introduction
The possibility of taking the advantage of particular properties of the constituent materials to meet
specific demands is the most important motivation for the development of composites In this way we
are working on varying the mechanosynthesised composites final structure for different purposes
Recently we have studied the processes of Al2O3Fe-Al [1] Fe2O3Fe3O4Fe [2] nanocomposites
mechanochemical formations The thermite solid state reduction reaction of α-Fe2O3 with metallic
reductant (Al Fe) was realized in those processes α-Fe2O was consistently reduced to Fe through
intermediate binary and ternary oxides Reduced Fe subsequent alloying with reductant surplus
resulted in Al2O3intermetallic phases composites formation The metal-reductant surplus in the
mixture leads to deceleration of Fe2O3 reduction and incapsulated structures formation Fe as
additional reductant caused some shift of the activation barrier of Fe2O3 reduction The ordering-
disordering phenomena led to amorphous iron-based magnetic phase formation in grain-boundary
regions This phase is stable for a long milling time and after heating up to 500oC [2] Its formation
creates the additional competitive process to Fe2O3 destruction To study the possibility of Fe2O3
mechanochemical reduction alloyed Fe-Al intermetallic compounds in high energy planetary ball mill
activation of pre-milled Fe+20Al mixture with Fe2O3 have been performed
2 Experimental
Ball milling of 8 g Fe powder with 2 g of Al powder was performed in AGO-2 planetary ball mill for
20 minutes in a vial sealed under Ar Then 3 g of α- Fe2O3 powder was added into 5 g of pre-milled
Fe-Al mixture and again subjected to 2 6 and 12 minute ball milling Vial volume was 250 cm3 Balls
diameter and mass were 5 mm and 200 g respectively The speed of drums rotation was ~1000 rpm
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
ccopy 2010 IOP Publishing Ltd 1
The 57
Fe Moumlssbauer spectra (MS) were recorded at room temperature with 57
Co(Rh) X-ray diffraction
(XRD) of as-milled and annealed powder samples was performed at Rigaku DXMax diffractometer
with Cu Kα radiation
3 Results and discussion X-ray diffraction image of Fe+20Al powder mixture milled for 20 min is shown in Fig1 (a) The
broadened peaks with maxima at the angles of FeAl may correspond not only to disordered (or even
amorphous) FeAl phase and its solid solution but also to structural reflections of FeAl2 and Fe2Al5
intermetallics also The presence of well resolved narrow Al peaks on the diffraction pattern indicate
unreacted Al
Moumlssbauer (Fig 2a) analysis of pre-milled Fe+20Al presented in bar diagram shows that
after 20 min of milling interaction between Fe and Al leads to the formation of highly disordered
composite consisted of FeAl Fe2Al5 and FeAl2 intermetallic phases and disordered Fe(Al) solid
solution We observed isomer shifts and quadrupole splittings change to some extent increased
linewidths of subspectra and even additional subspectra appearence in the case of FeAl phase As was
observed [4] FeAl disordering leads to the magnetically split component being resolved in addition to
the non-magnetic singlet Thus after 20 minutes of high energy ball milling of Fe+20Al we obtain
intermetallic phase composite
Figure 1 XRD pattern for 20 minutes ball milling Fe+20Al (a) mechanoactivated Fe+20Al
composite and Fe2O3 simply mixed (b) and mechanoactivated during 2(c) 6(d) and 12(e)
minutes
2 0 4 0 6 0 8 0 1 0 0
0
1 0 0 0
2 0 0 0
3 0 0 0
e )
d )
c )
b )
a )
Int
Int
Int
Fe
(20
0)
Fe
Al(
20
0)
Fe
Al(
20
0)
FeA
l(1
00)
Fe
(22
0)
Fe
Al(
21
1)
Fe(2
00
)
Fe(2
20
)
2 Θ
2 0 4 0 6 0 8 0 1 0 0
0
1 0 0 0
2 0 0 0
3 0 0 0
FeA
l(200)
Fe
Al(
200
)
Fe
2O
3(1
13
)
Fe
(11
0)
Fe
Al(
110
)
Fe3
O4
(44
0)
Fe
Al(
10
0)
Fe3
O4
(31
1)
Fe
(110
)F
eA
l(11
0)
Fe
(20
0)
Fe
Al(
211
)
Fe
(22
0)
2 0 4 0 6 0 8 0 1 0 0
0
5 0 0
1 0 0 0
1 5 0 0
2 0 0 0
Fe(2
20)
Fe2
O3(1
0 1
0)
Fe(2
20)
Fe
Al(2
11
)
Fe
3O
4(4
40
)
Fe
3O
4(3
11
)
Fe
2O
3(3
00
)
Fe
2O
3(2
14
)
Fe2O
3(1
16)
Fe2
O3
(02
4)
Fe2O
3(1
13)
Fe2O
3(1
10)
Fe2O
3(1
04)
FeA
l(10
0)
Fe2O
3(0
12
)
2 0 4 0 6 0 8 0 1 0 0
0
5 0 0
1 0 0 0
1 5 0 0
Fe
Al 2
(11
0)
Fe
(220
)
Fe
Al(2
11)
FeA
l(10
0)
Fe
Al(
110
)
Fe
2O
3(2
20
)
Fe2O
3(2
26)
Fe2O
3(2
1 1
0)
Fe2O
3(1
0 1
0)
Fe
(22
0)
Fe(2
20)
Fe
Al(2
11)
Fe
(200
)
Fe2O
3(0
18)
Fe(1
10)
FeA
l(110)
Fe
(110
)F
eA
l(11
0)
Fe2O
3(3
00)
Fe2O
3(2
14)
Fe
2O
3(0
18
)
Fe2
O3(1
16)
Fe
2O
3(0
24
)
Fe2O
3(1
13)
Fe
2O
3(1
10
)
Fe2
O3
(10
4)
Fe2
O3(0
12)
2 0 4 0 6 0 8 0 1 0 0
0
4 0 0 0
8 0 0 0
1 2 0 0 0
Fe
Al(
20
0)
Fe
Al(
211
)A
l(22
2)
Al(
11
1)
Fe
Al(1
00)
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
2
The XRD pattern (Fig 1b) and Moumlssbauer spectrum (Fig 2b) of simple mixture Fe2O3 and pre-
activated Fe-Al composite correspond to mixed components contributions in the ratio 12 The percent
of intermetallics component is about 60 that indicate metallic component prevalence
As is seen from XRD pictures (Fig 1 cde) the subsequent milling of this mixture results in
phase transformations arising from the Fe2O3 and Fe-Al composite interaction Fe2O3 destruction after
2 min is reflected in its intensity decrease and structure peaks widening is observed The main wide
composite intermetallic peak becomes narrow Al peaks disappeared fully According to Moumlssbauer
data (Fig 2c) the mixture after 2 min contains Fe2O3 Fe3O4 Fe and 42 of a disordered
intermetallics mixture Milling for 6 min (Fig 1 d Fig 2) reveals Fe2O3 peaks disappearance on XRD
pattern and wide Fe3O4 maxima rise Moumlssbauer data confirm that the mixture is composed of Fe2O3
Fe3O4 and disordered intermetallics mixture It is interesting that at this time of milling traces of
ternary compound FeAl2O4 were detected Finally after 12 min (Fig 1 e) the XRD pattern consists of
only wide and asymmetric maxima which reflect the bcc α-Fe(Al) solid solution formation Moumlssbauer
spectrum (Fig 2) analysis reveal not only α-Fe(Al) formation but also disordered intermetallics and
ternary oxide Generally analyzing Moumlssbauer data of different milling time gradually Al rich
intermetallic phases decrease in accordance with hematite reduction and bcc α-Fe(Al) solid solution
Figure 2 Moumlssbauer spectra and phase diagrams of pre-milled Fe+20Al (a) pre-milled
Fe+20Al simply mixed with Fe2O3(b) mechanoactivated during 2(c) 6(d) and 12(e) minutes
-10 -5 0 5 10090
092
094
096
098
100
S
0
20
40
60
80
100
b)
a )
Fe
Al 2
Fe
3O
4
Fe
Fe
Fe
Al 2
dis
ord
Fe
Al
Fe
Al 2
Fe
2A
l 5
-10 -5 0 5 10090
092
094
096
098
100
S
e)
d )
c)0
20
40
60
80
100
dis
ord
Fe
2A
l 5
Fe
2O
3
Fe(A
l)
FeA
l
Fe
2O
3F
e2O
3
-10 -5 0 5 10090
092
094
096
098
100
102
S
0
20
40
60
80
100
Fe
2A
l 5
dis
ord
Fe
3O
4
Fe
(Al)
Fe
(Al)
Fe
Al
-10 -5 0 5 10
090
092
094
096
098
100
S
V m m s
0
20
40
60
80
100
Fe
Al 2O
4
dis
ord
Fe
Al 2
O4
FeA
l
-10 -5 0 5 10
088
092
096
100
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
0
20
40
60
80
100
S
Fe
Al 2
Fe
Al
dis
ord
Fe
2A
l 5
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
3
formation is clearly detected It should be noted that no oxide phases of aluminum were detected on
XRD pattern which is assumed due to possible X-ray amorphous modification of it Evaluation of
aluminum concentration in a-Fe(Al) solid solution was performed by analysis of hyperfine fields
distribution of the corresponding Moumlssbauer spectrum component (Fig 2 (e)) and reveals the value 7
at
Figure 3 The fraction of Fe2O3 depending on
milling time t in (a) the system under study (b) in
comparison with analogous systems α-Fe2O3 + Al
and (c) α-Fe2O3 + Al + Fe
Fig 3 demonstrates the kinetics of Fe2O3 destruction in different powder mixture with equal surplus of
metal reductant component subjected to high energy ball milling Amorphous phase formation in the
presence of iron compounds leads to the slowing down the oxide reduction process
4 Conclusions
Moumlssbauer spectroscopy and X-ray diffraction study of subsequent interaction of α-Fe2O3 with pre-
mechanoactivated Fe+20Al composite powder mixture reveal gradual α-Fe2O3 reduction via
formation of iron binary and ternary oxides up to Fe On the other hand Fe-Al mechanocomposite
transformations lead to disordered α-Fe(Al) solid solution and Fe-based amorphous phase formation
Complete amorphous phase formation on the iron surface decreases its reductant ability and slows
down the process of α-Fe2O3 reduction in comparison with the analogous systems
References
[1] AANovakova TYuKiseleva et al 14th IntSymp on Metastable and Nano-MaterISMANAM-
2007 Corfu Greece Proceed 179 (2007)
[2] TYuKiseleva AANovakova MIChystyakova AOPolyakov et al Solid State Phenomena
152-153 25-28 (2009)
[3] TYuKiseleva AANovakova TFGrigorieva et al Advanced materials 6 1-10 (2008)
[4] SGialanella XAmils et al Acta mater 46 3305 (1998)
0 100 200 300 400 500 600 700 800
0
20
40
60
80
100
c b
F
e2
O3
t sec
a
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
4
The 57
Fe Moumlssbauer spectra (MS) were recorded at room temperature with 57
Co(Rh) X-ray diffraction
(XRD) of as-milled and annealed powder samples was performed at Rigaku DXMax diffractometer
with Cu Kα radiation
3 Results and discussion X-ray diffraction image of Fe+20Al powder mixture milled for 20 min is shown in Fig1 (a) The
broadened peaks with maxima at the angles of FeAl may correspond not only to disordered (or even
amorphous) FeAl phase and its solid solution but also to structural reflections of FeAl2 and Fe2Al5
intermetallics also The presence of well resolved narrow Al peaks on the diffraction pattern indicate
unreacted Al
Moumlssbauer (Fig 2a) analysis of pre-milled Fe+20Al presented in bar diagram shows that
after 20 min of milling interaction between Fe and Al leads to the formation of highly disordered
composite consisted of FeAl Fe2Al5 and FeAl2 intermetallic phases and disordered Fe(Al) solid
solution We observed isomer shifts and quadrupole splittings change to some extent increased
linewidths of subspectra and even additional subspectra appearence in the case of FeAl phase As was
observed [4] FeAl disordering leads to the magnetically split component being resolved in addition to
the non-magnetic singlet Thus after 20 minutes of high energy ball milling of Fe+20Al we obtain
intermetallic phase composite
Figure 1 XRD pattern for 20 minutes ball milling Fe+20Al (a) mechanoactivated Fe+20Al
composite and Fe2O3 simply mixed (b) and mechanoactivated during 2(c) 6(d) and 12(e)
minutes
2 0 4 0 6 0 8 0 1 0 0
0
1 0 0 0
2 0 0 0
3 0 0 0
e )
d )
c )
b )
a )
Int
Int
Int
Fe
(20
0)
Fe
Al(
20
0)
Fe
Al(
20
0)
FeA
l(1
00)
Fe
(22
0)
Fe
Al(
21
1)
Fe(2
00
)
Fe(2
20
)
2 Θ
2 0 4 0 6 0 8 0 1 0 0
0
1 0 0 0
2 0 0 0
3 0 0 0
FeA
l(200)
Fe
Al(
200
)
Fe
2O
3(1
13
)
Fe
(11
0)
Fe
Al(
110
)
Fe3
O4
(44
0)
Fe
Al(
10
0)
Fe3
O4
(31
1)
Fe
(110
)F
eA
l(11
0)
Fe
(20
0)
Fe
Al(
211
)
Fe
(22
0)
2 0 4 0 6 0 8 0 1 0 0
0
5 0 0
1 0 0 0
1 5 0 0
2 0 0 0
Fe(2
20)
Fe2
O3(1
0 1
0)
Fe(2
20)
Fe
Al(2
11
)
Fe
3O
4(4
40
)
Fe
3O
4(3
11
)
Fe
2O
3(3
00
)
Fe
2O
3(2
14
)
Fe2O
3(1
16)
Fe2
O3
(02
4)
Fe2O
3(1
13)
Fe2O
3(1
10)
Fe2O
3(1
04)
FeA
l(10
0)
Fe2O
3(0
12
)
2 0 4 0 6 0 8 0 1 0 0
0
5 0 0
1 0 0 0
1 5 0 0
Fe
Al 2
(11
0)
Fe
(220
)
Fe
Al(2
11)
FeA
l(10
0)
Fe
Al(
110
)
Fe
2O
3(2
20
)
Fe2O
3(2
26)
Fe2O
3(2
1 1
0)
Fe2O
3(1
0 1
0)
Fe
(22
0)
Fe(2
20)
Fe
Al(2
11)
Fe
(200
)
Fe2O
3(0
18)
Fe(1
10)
FeA
l(110)
Fe
(110
)F
eA
l(11
0)
Fe2O
3(3
00)
Fe2O
3(2
14)
Fe
2O
3(0
18
)
Fe2
O3(1
16)
Fe
2O
3(0
24
)
Fe2O
3(1
13)
Fe
2O
3(1
10
)
Fe2
O3
(10
4)
Fe2
O3(0
12)
2 0 4 0 6 0 8 0 1 0 0
0
4 0 0 0
8 0 0 0
1 2 0 0 0
Fe
Al(
20
0)
Fe
Al(
211
)A
l(22
2)
Al(
11
1)
Fe
Al(1
00)
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
2
The XRD pattern (Fig 1b) and Moumlssbauer spectrum (Fig 2b) of simple mixture Fe2O3 and pre-
activated Fe-Al composite correspond to mixed components contributions in the ratio 12 The percent
of intermetallics component is about 60 that indicate metallic component prevalence
As is seen from XRD pictures (Fig 1 cde) the subsequent milling of this mixture results in
phase transformations arising from the Fe2O3 and Fe-Al composite interaction Fe2O3 destruction after
2 min is reflected in its intensity decrease and structure peaks widening is observed The main wide
composite intermetallic peak becomes narrow Al peaks disappeared fully According to Moumlssbauer
data (Fig 2c) the mixture after 2 min contains Fe2O3 Fe3O4 Fe and 42 of a disordered
intermetallics mixture Milling for 6 min (Fig 1 d Fig 2) reveals Fe2O3 peaks disappearance on XRD
pattern and wide Fe3O4 maxima rise Moumlssbauer data confirm that the mixture is composed of Fe2O3
Fe3O4 and disordered intermetallics mixture It is interesting that at this time of milling traces of
ternary compound FeAl2O4 were detected Finally after 12 min (Fig 1 e) the XRD pattern consists of
only wide and asymmetric maxima which reflect the bcc α-Fe(Al) solid solution formation Moumlssbauer
spectrum (Fig 2) analysis reveal not only α-Fe(Al) formation but also disordered intermetallics and
ternary oxide Generally analyzing Moumlssbauer data of different milling time gradually Al rich
intermetallic phases decrease in accordance with hematite reduction and bcc α-Fe(Al) solid solution
Figure 2 Moumlssbauer spectra and phase diagrams of pre-milled Fe+20Al (a) pre-milled
Fe+20Al simply mixed with Fe2O3(b) mechanoactivated during 2(c) 6(d) and 12(e) minutes
-10 -5 0 5 10090
092
094
096
098
100
S
0
20
40
60
80
100
b)
a )
Fe
Al 2
Fe
3O
4
Fe
Fe
Fe
Al 2
dis
ord
Fe
Al
Fe
Al 2
Fe
2A
l 5
-10 -5 0 5 10090
092
094
096
098
100
S
e)
d )
c)0
20
40
60
80
100
dis
ord
Fe
2A
l 5
Fe
2O
3
Fe(A
l)
FeA
l
Fe
2O
3F
e2O
3
-10 -5 0 5 10090
092
094
096
098
100
102
S
0
20
40
60
80
100
Fe
2A
l 5
dis
ord
Fe
3O
4
Fe
(Al)
Fe
(Al)
Fe
Al
-10 -5 0 5 10
090
092
094
096
098
100
S
V m m s
0
20
40
60
80
100
Fe
Al 2O
4
dis
ord
Fe
Al 2
O4
FeA
l
-10 -5 0 5 10
088
092
096
100
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
0
20
40
60
80
100
S
Fe
Al 2
Fe
Al
dis
ord
Fe
2A
l 5
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
3
formation is clearly detected It should be noted that no oxide phases of aluminum were detected on
XRD pattern which is assumed due to possible X-ray amorphous modification of it Evaluation of
aluminum concentration in a-Fe(Al) solid solution was performed by analysis of hyperfine fields
distribution of the corresponding Moumlssbauer spectrum component (Fig 2 (e)) and reveals the value 7
at
Figure 3 The fraction of Fe2O3 depending on
milling time t in (a) the system under study (b) in
comparison with analogous systems α-Fe2O3 + Al
and (c) α-Fe2O3 + Al + Fe
Fig 3 demonstrates the kinetics of Fe2O3 destruction in different powder mixture with equal surplus of
metal reductant component subjected to high energy ball milling Amorphous phase formation in the
presence of iron compounds leads to the slowing down the oxide reduction process
4 Conclusions
Moumlssbauer spectroscopy and X-ray diffraction study of subsequent interaction of α-Fe2O3 with pre-
mechanoactivated Fe+20Al composite powder mixture reveal gradual α-Fe2O3 reduction via
formation of iron binary and ternary oxides up to Fe On the other hand Fe-Al mechanocomposite
transformations lead to disordered α-Fe(Al) solid solution and Fe-based amorphous phase formation
Complete amorphous phase formation on the iron surface decreases its reductant ability and slows
down the process of α-Fe2O3 reduction in comparison with the analogous systems
References
[1] AANovakova TYuKiseleva et al 14th IntSymp on Metastable and Nano-MaterISMANAM-
2007 Corfu Greece Proceed 179 (2007)
[2] TYuKiseleva AANovakova MIChystyakova AOPolyakov et al Solid State Phenomena
152-153 25-28 (2009)
[3] TYuKiseleva AANovakova TFGrigorieva et al Advanced materials 6 1-10 (2008)
[4] SGialanella XAmils et al Acta mater 46 3305 (1998)
0 100 200 300 400 500 600 700 800
0
20
40
60
80
100
c b
F
e2
O3
t sec
a
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
4
The XRD pattern (Fig 1b) and Moumlssbauer spectrum (Fig 2b) of simple mixture Fe2O3 and pre-
activated Fe-Al composite correspond to mixed components contributions in the ratio 12 The percent
of intermetallics component is about 60 that indicate metallic component prevalence
As is seen from XRD pictures (Fig 1 cde) the subsequent milling of this mixture results in
phase transformations arising from the Fe2O3 and Fe-Al composite interaction Fe2O3 destruction after
2 min is reflected in its intensity decrease and structure peaks widening is observed The main wide
composite intermetallic peak becomes narrow Al peaks disappeared fully According to Moumlssbauer
data (Fig 2c) the mixture after 2 min contains Fe2O3 Fe3O4 Fe and 42 of a disordered
intermetallics mixture Milling for 6 min (Fig 1 d Fig 2) reveals Fe2O3 peaks disappearance on XRD
pattern and wide Fe3O4 maxima rise Moumlssbauer data confirm that the mixture is composed of Fe2O3
Fe3O4 and disordered intermetallics mixture It is interesting that at this time of milling traces of
ternary compound FeAl2O4 were detected Finally after 12 min (Fig 1 e) the XRD pattern consists of
only wide and asymmetric maxima which reflect the bcc α-Fe(Al) solid solution formation Moumlssbauer
spectrum (Fig 2) analysis reveal not only α-Fe(Al) formation but also disordered intermetallics and
ternary oxide Generally analyzing Moumlssbauer data of different milling time gradually Al rich
intermetallic phases decrease in accordance with hematite reduction and bcc α-Fe(Al) solid solution
Figure 2 Moumlssbauer spectra and phase diagrams of pre-milled Fe+20Al (a) pre-milled
Fe+20Al simply mixed with Fe2O3(b) mechanoactivated during 2(c) 6(d) and 12(e) minutes
-10 -5 0 5 10090
092
094
096
098
100
S
0
20
40
60
80
100
b)
a )
Fe
Al 2
Fe
3O
4
Fe
Fe
Fe
Al 2
dis
ord
Fe
Al
Fe
Al 2
Fe
2A
l 5
-10 -5 0 5 10090
092
094
096
098
100
S
e)
d )
c)0
20
40
60
80
100
dis
ord
Fe
2A
l 5
Fe
2O
3
Fe(A
l)
FeA
l
Fe
2O
3F
e2O
3
-10 -5 0 5 10090
092
094
096
098
100
102
S
0
20
40
60
80
100
Fe
2A
l 5
dis
ord
Fe
3O
4
Fe
(Al)
Fe
(Al)
Fe
Al
-10 -5 0 5 10
090
092
094
096
098
100
S
V m m s
0
20
40
60
80
100
Fe
Al 2O
4
dis
ord
Fe
Al 2
O4
FeA
l
-10 -5 0 5 10
088
092
096
100
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
Re
lIn
ten
sity
0
20
40
60
80
100
S
Fe
Al 2
Fe
Al
dis
ord
Fe
2A
l 5
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
3
formation is clearly detected It should be noted that no oxide phases of aluminum were detected on
XRD pattern which is assumed due to possible X-ray amorphous modification of it Evaluation of
aluminum concentration in a-Fe(Al) solid solution was performed by analysis of hyperfine fields
distribution of the corresponding Moumlssbauer spectrum component (Fig 2 (e)) and reveals the value 7
at
Figure 3 The fraction of Fe2O3 depending on
milling time t in (a) the system under study (b) in
comparison with analogous systems α-Fe2O3 + Al
and (c) α-Fe2O3 + Al + Fe
Fig 3 demonstrates the kinetics of Fe2O3 destruction in different powder mixture with equal surplus of
metal reductant component subjected to high energy ball milling Amorphous phase formation in the
presence of iron compounds leads to the slowing down the oxide reduction process
4 Conclusions
Moumlssbauer spectroscopy and X-ray diffraction study of subsequent interaction of α-Fe2O3 with pre-
mechanoactivated Fe+20Al composite powder mixture reveal gradual α-Fe2O3 reduction via
formation of iron binary and ternary oxides up to Fe On the other hand Fe-Al mechanocomposite
transformations lead to disordered α-Fe(Al) solid solution and Fe-based amorphous phase formation
Complete amorphous phase formation on the iron surface decreases its reductant ability and slows
down the process of α-Fe2O3 reduction in comparison with the analogous systems
References
[1] AANovakova TYuKiseleva et al 14th IntSymp on Metastable and Nano-MaterISMANAM-
2007 Corfu Greece Proceed 179 (2007)
[2] TYuKiseleva AANovakova MIChystyakova AOPolyakov et al Solid State Phenomena
152-153 25-28 (2009)
[3] TYuKiseleva AANovakova TFGrigorieva et al Advanced materials 6 1-10 (2008)
[4] SGialanella XAmils et al Acta mater 46 3305 (1998)
0 100 200 300 400 500 600 700 800
0
20
40
60
80
100
c b
F
e2
O3
t sec
a
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
4
formation is clearly detected It should be noted that no oxide phases of aluminum were detected on
XRD pattern which is assumed due to possible X-ray amorphous modification of it Evaluation of
aluminum concentration in a-Fe(Al) solid solution was performed by analysis of hyperfine fields
distribution of the corresponding Moumlssbauer spectrum component (Fig 2 (e)) and reveals the value 7
at
Figure 3 The fraction of Fe2O3 depending on
milling time t in (a) the system under study (b) in
comparison with analogous systems α-Fe2O3 + Al
and (c) α-Fe2O3 + Al + Fe
Fig 3 demonstrates the kinetics of Fe2O3 destruction in different powder mixture with equal surplus of
metal reductant component subjected to high energy ball milling Amorphous phase formation in the
presence of iron compounds leads to the slowing down the oxide reduction process
4 Conclusions
Moumlssbauer spectroscopy and X-ray diffraction study of subsequent interaction of α-Fe2O3 with pre-
mechanoactivated Fe+20Al composite powder mixture reveal gradual α-Fe2O3 reduction via
formation of iron binary and ternary oxides up to Fe On the other hand Fe-Al mechanocomposite
transformations lead to disordered α-Fe(Al) solid solution and Fe-based amorphous phase formation
Complete amorphous phase formation on the iron surface decreases its reductant ability and slows
down the process of α-Fe2O3 reduction in comparison with the analogous systems
References
[1] AANovakova TYuKiseleva et al 14th IntSymp on Metastable and Nano-MaterISMANAM-
2007 Corfu Greece Proceed 179 (2007)
[2] TYuKiseleva AANovakova MIChystyakova AOPolyakov et al Solid State Phenomena
152-153 25-28 (2009)
[3] TYuKiseleva AANovakova TFGrigorieva et al Advanced materials 6 1-10 (2008)
[4] SGialanella XAmils et al Acta mater 46 3305 (1998)
0 100 200 300 400 500 600 700 800
0
20
40
60
80
100
c b
F
e2
O3
t sec
a
International Conference on the Applications of the Moumlssbauer Effect (ICAME 2009) IOP PublishingJournal of Physics Conference Series 217 (2010) 012081 doi1010881742-65962171012081
4