Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy
The effect of preliminary pressure treatment (PT) on peculiarities of changes in electrical resistance R and structure of the amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy during a constantrate heating to temperatures under the crystallization onset temperature has been studied using the resistance measurement a...
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Донецький фізико-технічний інститут ім. О.О. Галкіна НАН України
2010
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| Цитувати: | Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy / V.N. Varyukhin, T.T. Moroz, V.S. Abramov // Физика и техника высоких давлений. — 2010. — Т. 20, № 1. — С. 82-89. — Бібліогр.: 12 назв. — англ. |
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irk-123456789-692652014-10-10T03:01:40Z Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy Varyukhin, V.N. Moroz, T.T. Abramov, V.S. The effect of preliminary pressure treatment (PT) on peculiarities of changes in electrical resistance R and structure of the amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy during a constantrate heating to temperatures under the crystallization onset temperature has been studied using the resistance measurement and X-ray diffraction (XRD) methods. Preliminary PT has been done at 300 K (P = 1 GPa) in the repetitive static mode for different number N of loading cycles (N = 1, 3, 5).The XRD data show that the amorphous state of the studied alloy is conserved but its fine structure has changed after PT, as observed by variation of halo parameters. It has been found that after PT with an increase in the number N of loading cycles, the ordering of the original amorphous structure is enhanced, while after heating from 828 to 843 K, the disordering growth is enhanced. Anomalies of R (a minimum at 497 K and a sharp rise in the range of 800–843 K) observed in the dependence R(T) of the original amorphous alloy are present after the PT too. They seem to be due to structural phase transitions of amorphous alloy during heating. Методами резистометрии и рентгеноструктурного анализа (РСА) изучено влияние предварительной обработки давлением (ОД) на особенности изменения электрического сопротивления R и структуры аморфного сплава Co₆₇Cr₇Fe₄Si₈B₁₄ при нагреве с постоянной скоростью до температур не выше температуры начала кристаллизации. ОД проведено при комнатной температуре в повторно-статическом режиме с разным числом N циклов обработки (N = 1, 3, 5) при давлении P = 1 GPa. По данным РСА, после ОД аморфное состояние изучаемого сплава сохраняется, но тонкая структура гало изменяется. Показано, что с ростом N циклов ОД растет упорядочение, а при нагреве в интервале 828–843 K – разупорядочение исходной аморфной структуры сплава. Аномалии R (минимум при 497 K и резкий рост в окрестности 800–843 K), наблюдаемые на зависимости R(T) исходного аморфного сплава, после ОД сохраняются и связаны, по-видимому, со структурными фазовыми переходами в процессе нагревания сплава. Методами резістометрії та рентгеноструктурного аналізу (РСА) вивчено вплив попередньої обробки тиском (ОТ) на особливості зміни електричного опору R та структуру аморфного сплаву при нагріванні з постійною швидкістю до температур, які не перевищують температуру початку кристалізації. ОТ проведено при кімнатнiй температурі у повторно-статичному режимі з різним числом N циклів навантаження (N = 1, 3, 5) при тиску Р = 1 GPa. За даними РСА, після ОТ аморфний стан сплаву, що вивчається, зберігається, але тонка структура гало змінюється. Показано, що зі зростанням N циклів ОТ зростає упорядкування, а при нагріванні в интервалі 828–843 K – розупорядкування вихідної структури сплаву. Аномалиії R (мінімум при 497 K та різке зростання в межах 800–843 K), які спостерігаються на залежності R(T) вихідного аморфного сплаву, після ОТ зберігаються та пов′язані, напевно, зі структурними фазовими перетвореннями аморфного сплаву у процесі нагрівання сплаву.. 2010 Article Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy / V.N. Varyukhin, T.T. Moroz, V.S. Abramov // Физика и техника высоких давлений. — 2010. — Т. 20, № 1. — С. 82-89. — Бібліогр.: 12 назв. — англ. 0868-5924 PACS: 81.40.Vw http://dspace.nbuv.gov.ua/handle/123456789/69265 en Физика и техника высоких давлений Донецький фізико-технічний інститут ім. О.О. Галкіна НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| description |
The effect of preliminary pressure treatment (PT) on peculiarities of changes in electrical resistance R and structure of the amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy during a constantrate heating to temperatures under the crystallization onset temperature has been studied using the resistance measurement and X-ray diffraction (XRD) methods. Preliminary PT has been done at 300 K (P = 1 GPa) in the repetitive static mode for different number N of loading cycles (N = 1, 3, 5).The XRD data show that the amorphous state of the studied alloy is conserved but its fine structure has changed after PT, as observed by variation of halo parameters. It has been found that after PT with an increase in the number N of loading cycles, the ordering of the original amorphous structure is enhanced, while after heating from 828 to 843 K, the disordering growth is enhanced. Anomalies of R (a minimum at 497 K and a sharp rise in the range of 800–843 K) observed in the dependence R(T) of the original amorphous alloy are present after the PT too. They seem to be due to structural phase transitions of amorphous alloy during heating. |
| format |
Article |
| author |
Varyukhin, V.N. Moroz, T.T. Abramov, V.S. |
| spellingShingle |
Varyukhin, V.N. Moroz, T.T. Abramov, V.S. Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy Физика и техника высоких давлений |
| author_facet |
Varyukhin, V.N. Moroz, T.T. Abramov, V.S. |
| author_sort |
Varyukhin, V.N. |
| title |
Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy |
| title_short |
Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy |
| title_full |
Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy |
| title_fullStr |
Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy |
| title_full_unstemmed |
Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy |
| title_sort |
influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous co₆₇cr₇fe₄si₈b₁₄ alloy |
| publisher |
Донецький фізико-технічний інститут ім. О.О. Галкіна НАН України |
| publishDate |
2010 |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/69265 |
| citation_txt |
Influence of preliminary hydrostatic pressure treatment on the electrical resistance and structure of amorphous Co₆₇Cr₇Fe₄Si₈B₁₄ alloy / V.N. Varyukhin, T.T. Moroz, V.S. Abramov // Физика и техника высоких давлений. — 2010. — Т. 20, № 1. — С. 82-89. — Бібліогр.: 12 назв. — англ. |
| series |
Физика и техника высоких давлений |
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2025-07-05T18:53:49Z |
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Физика и техника высоких давлений 2010, том 20, № 1
© V.N. Varyukhin, T.T. Moroz, V.S. Abramov, 2010
PACS: 81.40.Vw
V.N. Varyukhin, T.T. Moroz, V.S. Abramov
INFLUENCE OF PRELIMINARY HYDROSTATIC PRESSURE
TREATMENT ON THE ELECTRICAL RESISTANCE AND STRUCTURE
OF AMORPHOUS Co67Cr7Fe4Si8B14 ALLOY
Donetsk Institute for Physics and Engineering named after A.A. Galkin, National Acad-
emy of Sciences of Ukraine
72 R. Luxemburg st., Donetsk, 83114, Ukraine
Received November 25, 2009
The effect of preliminary pressure treatment (PT) on peculiarities of changes in electrical
resistance R and structure of the amorphous Co67Cr7Fe4Si8B14 alloy during a constant-
rate heating to temperatures under the crystallization onset temperature has been studied
using the resistance measurement and X-ray diffraction (XRD) methods. Preliminary PT
has been done at 300 K (P = 1 GPa) in the repetitive static mode for different number N
of loading cycles (N = 1, 3, 5).The XRD data show that the amorphous state of the stud-
ied alloy is conserved but its fine structure has changed after PT, as observed by varia-
tion of halo parameters. It has been found that after PT with an increase in the number N
of loading cycles, the ordering of the original amorphous structure is enhanced, while
after heating from 828 to 843 K, the disordering growth is enhanced. Anomalies of R (a
minimum at 497 K and a sharp rise in the range of 800–843 K) observed in the depend-
ence R(T) of the original amorphous alloy are present after the PT too. They seem to be
due to structural phase transitions of amorphous alloy during heating.
Keywords: hydrostatic pressure, amorphous alloy, structure, halo, electrical resistance
1. Introduction
Amorphous metal alloys (AA) refer to thermodynamically nonequilibrium
systems in which the structure relaxation and crystallization processes develop
under an external influence, such as temperature, pressure, deformation, etc.
High-pressure effect on AA crystallization process gives changes in the tempera-
ture Ts of crystallization onset and in the sequence of crystalline phase precipita-
tion, thus favoring the formation of structures with a more close packing of atoms.
Most literary data [1–3] show that there is an increase in Ts with pressure growth
during heating the AA under pressure. The conventional explanation is as follows.
As the diffusion-controlled process of AA crystallization proceeds by the nuclea-
tion and the growth mechanism, the pressure results in decreasing the diffusion
mobility of atoms and, as a consequence, in a more difficult crystallization proc-
Физика и техника высоких давлений 2010, том 20, № 1
83
ess, i.e. in Ts increase. However, for a number of alloys (Ti80Si20, Al89La6Ni5) an
opposite effect is observed, viz. Ts decreases with pressure increase. A thermody-
namic model [4] has been proposed to describe the nucleation process during AA
crystallization under pressure with a special attention paid to the formation (espe-
cially at early stages) of the amorphous–crystalline phase interface. Calculations
done within the model explain both the increase (for amorphous Se and Ni80P20)
and decrease (for Al89La6Ni5) of AA thermal stability under pressure.
Of obvious interest is the behaviour of some AA of the Co–Fe–Cr–Si–B sys-
tem in the process of crystallization. According to Cziraki et al. [5], the crystalli-
zation of Fe–M–B–Si (M = Co, Cr, Mn, Ni) amorphous alloys results in a specific
microstructure which is presumably composed of nanocrystals 1–3 nm in diame-
ter. In addition, the process is accompanied by a pronounced heat release and
anomalous rise in the resistance R in the corresponding temperature range. The
amorphous Co67Cr7Fe4Si8B14 alloy under study shows a similar behaviour of R
during heating. We have studied the effect of preliminary pressure treatment (PT)
on nanocrystallization process for this alloy [6]. It has been shown that after PT,
the thermal stability of the alloy decreases. Nanocrystallization mechanism, se-
quence of the crystalline phase precipitation and the phase composition of the
crystallization products do not change. And there is a tendency to reducing the
crystal dimensions of the stable crystalline phase.
This paper is aimed at studying the influence of hydrostatic pressure treatment
on peculiarities of changes in electrical resistance and structure of the amorphous
Co67Cr7Fe4Si8B14 alloy during a constant-rate heating to temperatures under the
crystallization onset temperature.
2. Experimental
The investigated was the amorphous Co67Cr7Fe4Si8B14 alloy prepared by melt
spinning to have a 12 mm wide and 0.03 mm thick tape. Preliminary PT was done at
300 K in a repetitive static mode with the number N = 1, 3 5 of loading cycles and at
P = 1 GPa. The samples having the dimension 0.03 × 1.5 × 25 mm were placed along
the axis of high-pressure chamber whose cavity was filled with a working fluid. The
chamber was loaded by means of a hand-power press. The rate of pressure pick up –
15 MPa/s, the rate of unloading – 6 MPa/s, the pressure was maintained for 180 s, and
nonhydrostaticity along liquid column – 4⋅10–3 GPa/mm for P = 1 GPa.
The resistance measurement and XRD methods have been used in this work.
The electrical resistance R of the samples was measured (the error of ±2⋅10–5 Ω)
by a standard four-probe dc method. The voltage at the sample (proportional to
ΔR) and temperature T (accuracy ±1.5 K) during the heating were recorded by a
dc six- channel KSP-4 potentiometer. The heating rate was maintained constant at
0.25 K/s. The results were analyzed in the form of R(T) dependence normalized to
value R0 measured at 300 K prior the sample heating. XRD photographs were
taken from polished sections in an RKU-114 Debye–Scherrer powder camera
(URS-55 X-ray generator, filtered cobalt radiation).
Физика и техника высоких давлений 2010, том 20, № 1
84
3. Results and discussion
The XRD data represented in Fig. 1 (curve 1) show the initial state of the al-
loy studied to be amorphous: microphotogram of the sample shows a broad dif-
fuse halo; there are no peaks corresponding to crystal phases. After preliminary
PT the amorphous state is conserved but its fine structure alters as shown by
changes in halo parameters such as the integrated width β1 and the relative inte-
grated intensity ξ (ξ = Ihalo/(Ihalo + Iincoh), where Ihalo and Iincoh are integrated
intensities of the halo and the incoherent scattering of X-rays from the studied
sample). With an increase in the number N of PT loading cycles, β1 decreases
while the degree of structure ordering ξ increases. The angle corresponding to
the maximum of halo does not change and responds to that of coordination
sphere of 0.1978 nm the most probable radius close to the position of the most
intense line of Co3B phase.
45 50 55 60 65
45
60
75
90
I,
a
rb
. u
ni
ts
3
4
2
1
Iincoh
Ihalo
2Θ, grad.
400 600 800
0.98
1.00
1.02
1.04
R
/R
0 803 K
828 K
843 K
T, K
Fig. 1. Microphotograms from Co67Cr7Fe4Si8B14 alloy without the PT (curve 1 – ξ = 0.5,
β1 = 7.8°) and after the PT: 2 – N = 1, ξ = 0.8, β1 = 7.4°; 3 – N = 3, ξ = 0.6, β1 = 7.2°; 4 –
N = 5, ξ = 0.8, β1 = 5.8°
Fig. 2. Temperature dependences of R/R0 for Co67Cr7Fe4Si8B14 alloy (the heating rate of
0.25 K/s) without (●) and after the PT for N = 1 (○), 3 (+), 5 (▼)
Fig. 2 illustrates the curves of changes in relative resistance R/R0 of alloy sam-
ples (without and past PT) for a constant rate heating to 873 K. The curves consist
of two distinct parts (300–773, 773–873 K). At first part, the attention is turned to
a smooth transition from negative to positive values of the temperature coefficient
of resistance with the minimum R/R0 (for the alloy without PT) at Tm = 497 K. For
the second range, R/R0 shows a sharp maximum at Ts = 843 K.
The temperature Tm is changed insignificantly for the samples after PT at N = 1
and N = 3, whereas it transforms into the temperature plateau of 493–503 K for
Физика и техника высоких давлений 2010, том 20, № 1
85
that after PT at N = 5. The value Ts for all the samples (with no and past PT) re-
mains constant and equals 843 K. And the larger the N of PT cycles the lower are
corresponding R/R0 curves for the samples past a preliminary PT.
The method of quenching was used to follow the evolution of diffraction patterns
from samples (without and past the PT) in the initial and heated states. The samples
were heated at the same (0.25 K/s) rate to temperatures corresponding to the singled
out points (Fig. 2, curve 1), water-quenched, then the XRD analysis was performed.
The results are shown in Figs. 3–5. The samples were heated once more to 873 K,
the resulting temperature dependences of R/R0 are illustrated in Fig. 6.
Within the cluster model and the representation on the presence of multimini-
mum potential, the AA structure could be represented as an ensemble of clusters
confined by more or less rigid bonds and of an intercluster layer. Then the dif-
fraction pattern from the AA samples is a result of X-ray scattering superposition
from those components of the structure. The intercluster layer is the main con-
tributor to the incoherent X-ray scattering. With the above representations taken
into consideration we have constructed curves I1(2θ) shown in Fig. 3 and 4 by
subtraction from the X-ray scattering intensity I(2θ), the incoherent scattering in-
tensity Iincoh(2θ) for the same (2θ) slip angle of a particular diffraction pattern. To
follow changes in curve profiles depending on PT and heating temperature, we
show the corresponding symmetric curves I2(2θ) by dotted lines. Under the figure,
45 50 55 60 65
0
10
20
30
40
50
60
I 1, a
rb
. u
ni
ts
2Θ, grad
4
3
2
1I2
44 48 52 56 60 64
0
10
20
30
40
I2
4
3
2
1
I 1, a
rb
. u
ni
ts
2Θ, grad
Fig. 3. Microphotograms from Co67Cr7Fe4Si8B14 alloy without the PT in as-quenched amor-
phous state (curve 1 – 2θm =53.8°, β1 = 7.8°, β2 = 6.9°, η = 0.63) and after heating followed by
water quenching: 2 – heating to 803 K, 2θm = 53.5°, β1 = 7.7°, β2 = 7.1°, η = 0.63; 3 – 828 K,
2θm = 53.8°, β1 = 8.0°, β2 = 7.6°, η = 0.65; 4 – 843 K, 2θm = 54.0°, β1 = β2 = 8.1°, η = 0.63
Fig. 4. Microphotograms from Co67Cr7Fe4Si8B14 alloy after the PT (N = 3) without
(curve 1 – 2θm = 53.8º, β1 = 7.2°, β2 = 6.8°, η = 0.56) and after heating followed by water
quenching: 2 – heating to 803 K, 2θm = 53.5°, β1 = 7.3°, β2 = 6.8°, η = 0.66; 3 – 828 K,
2θm = 53.8º, β1 = 7.5º, β2 = 7.3°, η = 0.70; 4 – 843 K, 2θm = 54.0°, β1 = β2 = 8.4°, η = 0.95
Физика и техника высоких давлений 2010, том 20, № 1
86
45 50 55 60 6540
50
60
70
80
90
100
4
3
2
1
2Θ, grad.
I,
ar
b.
u
ni
ts
400 600 800
T, K
4
3
2
1
R/
R 0, a
rb
. u
ni
ts
Fig. 5. Microphotograms from Co67Cr7Fe4Si8B14 alloy after heating to 843 K followed
by water quenching: without the PT (curve 1 – δ = 2.8%) and after the PT for N = 1, δ =
= 2.8% (curve 2); N = 3, δ = 6.2% (3); N = 5, δ = 6.7% (4)
Fig. 6. Temperature dependences of R/R0 for Co67Cr7Fe4Si8B14 alloy (heating rate 0.25
K/s) without PT in as-quenched amorphous state (curve 1) and after heating followed by
water quenching: 2 – heating to 828 K; 3 – 843 K; 4 – 843 K (after the PT, N = 5)
values 2θm, of the maximum intensity angles, β1 and β2 of curves I1(2θ) and I2(2θ)
and values of η = Hincoh/Hcoh (Hincoh, Hcoh – the maximum intensities of the inco-
herent and coherent (halo) X-ray scattering in the studied interval 2θ = 45–65°)
are shown.
The amorphous state of metal alloys is unstable from thermodynamic point of
view, that is why a preliminary PT, the same as any external influence, will, in our
opinion, favour the development of structural relaxation process. The XRD results
(Figs. 1, 3, 4) show that after PT there are irreversible changes in the as-prepared
amorphous alloy structure: an increase in N of the PT cycles, ξ which is a measure
of structure ordering, grows, while β1, β2 and halo asymmetry decrease. It points
to the fact that the processes of ordering and decreasing of the internal stress level
are in progress in the original amorphous structure of studied alloy after the PT.
We back up the opinion [7] that the irreversible structural relaxation is a process
related mainly to a change in the topological short-range order of atoms in AA, it
proceeds through the recombination or annihilation of the n–p pairs of the struc-
ture defects. The n-type defects are similar to dispersed free volume elements, and
the p-type defects are the centers of the positive local density fluctuations of
structure and might be considered as the anti-free volume. Under heating the de-
fects are redistributed, most probably they are split on a smaller and more stable
ones. Being participants of atomic transfer they may influence the AA thermal
stability.
Физика и техника высоких давлений 2010, том 20, № 1
87
As seen from Figs 3–4, the halo asymmetry decreases and finally it becomes
negligible with an increase in the samples (without and after PT) heating tem-
perature to 843 K. Then, magnitude η, a measure of structure disordering, does
not change practically for samples without the PT, but it grows with an increase in
N of the preliminary PT cycles. At the temperature of 843 K there is, on the one
hand, the maximum of R on the R/R0 curves (Fig. 2) and, on the other hand, on the
halo background there are clear indications of the crystal phases (Fig. 5). The vol-
ume fraction δ of the crystal phases in the samples after the PT for N = 3 and N = 5
is twice as large as in that with no the PT and after it for N = 1 (δ = Icr/(Icr + Ihalo);
Icr, Ihalo – integrated intensities of the X-ray scattering from the crystal and amor-
phous phases). The latter circumstance gives grounds to assume that after the pre-
liminary PT (N = 3 and N = 5) the thermal stability of the alloy is decreased.
The sharp rise in R (Fig. 2) observed near Ts in some Co-, Ni-, and Zr-based
AA [5,8,9] is mainly explained by two reasons. First, by the process of nanocrys-
tallization which occurs, according to authors [5] simultaneously throughout the
sample via composition fluctuations on a wavelength of 10–30 Ǻ and leads to a
rise in electrical resistance similar to that during the aging of crystalline alloys,
which results from the formation of Guinuer–Preston zones. However, the elec-
tron-microscope examination revealed no crystalline phase in the samples
quenched from Ts, and their electron diffraction patterns showed only amorphous
halo. In [9], it was assumed that the second reason is a change in the scattering
mechanism of conduction electrons near Ts, where the amorphous alloys seem to
be similar to overcooled liquids, rather than solid glasses.
Our results can confirm that the first explanation is true: after the heating fol-
lowed by quenching from 843 K (Fig. 5) in AA structure a crystalline phase has
been observed. On the other hand, value of electrical resistance growth R843/R800 ≈ 1.03
(see Fig. 2) is close to the jump in R for Co solid–liquid transition [11]. Besides, the
analysis of R/R0 curves (Fig. 6) shows that a 3% crystal phase presence has, during
the reheating, resulted in disappearance of the sharp rise of R, in the samples (with-
out the PT). However for the samples (after PT, N = 5) containing 6% crystal phase,
(curve 4) the effect was observed. The shape of curve 4 is very different from that
of the initial curve 4 in Fig. 2. As a whole, the behaviour of the R/R0 curves of Fig.
6 points to a complex character of the mechanism of charge-carrier scattering with
their localization and delocalization at structure non-uniformities.
We relate the minimum of R on the R/R0 curves at temperature Tm (see Fig. 2)
to a structural phase transition of the original amorphous state during alloy heat-
ing. Similar temperature dependences of R/R0 were reported for a number of
amorphous alloys and were, as a rule, interpreted as those due to changes of the
carrier scattering mechanism at structural fluctuations, which are accompanied by
the Kondo effect or the Anderson tunneling. If structural units of the amorphous
state are magnetic, the temperature of the phase transition may coincide with that
of the magnetic transition [11]. For example, from the magnetic susceptibility data
for the amorphous Co66.6Fe4.9Cr6.9Si7.6B15 alloy of composition close to the pres-
Физика и техника высоких давлений 2010, том 20, № 1
88
ently discussed one, Degro et al. [12] obtained the magnetic phase transition tem-
perature Tc = 493 K, which is nearly close to the temperature of structural transi-
tion (497 K) in our alloy.
4. Conclusion
The XRD data show that the amorphous state of the studied alloy is conserved
but its fine structure has changed after PT. It has been found that after PT with an
increase in the number N of PT loading cycles, the ordering of the original amor-
phous structure is enhanced, while after heating from 828 to 843 K, the disorder-
ing growth is observed.
Anomalies of the electrical resistance R (the minimum at 497 K and the sharp
rise in the range of 800–843 K) in R/R0 curves for the as-quenched amorphous
alloy are conserved after the preliminary PT and are evidently related to structural
phase transitions. The behaviour of R for thermally treated samples points to a
complex character of the mechanism of carrier scattering at structure defects.
1. W.K. Wang, H. Iwasaki, C. Suryanarayna, T. Masumoto, K. Fukamichi, Y. Syono, T. Goto,
in: Proc. 4th. Int. Conf. on Rapidly Quenched Metals, Sendai (1981), p. 663.
2. Y. Ogama, K. Nunogaki, S. Endo, M. Kiritani, F.F. Fujita, in: Proc. 4th. Int. Conf. on
Rapidly Quenched Metals, Sendai (1981), p. 675
3. B. Varga, A. Lovas, F. Ye, X.J. Gu, K. Lu, Mater. Sci. Eng. A286, 193 (2000).
4. F. Ye, K. Lu, Phys. Rev. B 60, 7018 (1999).
5. A. Cziraki, B. Fogarassy, I. Szabo, B. Albert, in: Proc. 4 th Int. Conf. on Rapidly
Quenched Metals, Sendai (1981), p. 691.
6. V.N. Varyukhin, Т.Т. Moroz, V.S. Abramov, V.G. Synkov, V.P. Kravchenko, High-
pressure Physics and Engineering 13, № 2, 7 (2003) (in Russian).
7. T. Egami, V. Vitek, D. Srolovitz, in: Proc. 4 th Int. Conf. on Rapidly Quenched Met-
als, Sendai (1981), p. 517.
8. K. Fukamihi, H.M. Kimura, T. Masumoto, J. Appl. Phys. 52, 2872 (1981)
9. O. Haruyama, H.M. Kimura, A. Inoue, Mater. Sci. Eng. A226–228, 209 (1997)
10. K. Handrich and S Kobe, Amorphe Ferro und Ferrimagnetika, Akademie, Berlin
(1980). Translated under the title Amorfnye Ferro- i Ferrimagnetiki, Mir, Moscow
(1982), p. 130–132.
11. A. Ubbelode, Melting and Crystal Structure, Calderon Press, Oxford (1965). Trans-
lated under the title Plavlenie i Kristallicheskaya Struktura, Mir, Moscow (1969),
p. 231.
12. J. Degro, P. Vojtanik, J. Filipensky, P. Duhaj, J. Magn. Magn. Mater. 117, 251 (1992).
Физика и техника высоких давлений 2010, том 20, № 1
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В.М. Варюхін, Т.Т. Мороз, В.С. Абрамов
ВПЛИВ ПОПЕРЕДНЬОЇ ОБРОБКИ ГІДРОСТАТИЧНИМ ТИСКОМ
НА ЕЛЕКТРИЧНИЙ ОПIР ТА СТРУКТУРУ АМОРФНОГО СПЛАВУ
Co67Cr7Fe4Si8B14
Методами резістометрії та рентгеноструктурного аналізу (РСА) вивчено вплив по-
передньої обробки тиском (ОТ) на особливості зміни електричного опору R та
структуру аморфного сплаву при нагріванні з постійною швидкістю до температур,
які не перевищують температуру початку кристалізації. ОТ проведено при кімнатнiй
температурі у повторно-статичному режимі з різним числом N циклів навантажен-
ня (N = 1, 3, 5) при тиску Р = 1 GPa. За даними РСА, після ОТ аморфний стан спла-
ву, що вивчається, зберігається, але тонка структура гало змінюється. Показано, що
зі зростанням N циклів ОТ зростає упорядкування, а при нагріванні в интервалі
828–843 K – розупорядкування вихідної структури сплаву. Аномалиії R (мінімум
при 497 K та різке зростання в межах 800–843 K), які спостерігаються на залеж-
ності R(T) вихідного аморфного сплаву, після ОТ зберігаються та пов′язані, напев-
но, зі структурними фазовими перетвореннями аморфного сплаву у процесі
нагрівання сплаву.
Ключові слова: гідростатичний тиск, аморфний сплав, структура, гало, електрич-
ний опір
В.Н. Варюхин, Т.Т. Мороз, В.С. Абрамов
ВЛИЯНИЕ ПРЕДВАРИТЕЛЬНОЙ ОБРАБОТКИ ГИДРОСТАТИЧЕСКИМ
ДАВЛЕНИЕМ НА ЭЛЕКТРИЧЕСКОЕ СОПРОТИВЛЕНИЕ
И СТРУКТУРУ АМОРФНОГО СПЛАВА Co67Cr7Fe4Si8B14
Методами резистометрии и рентгеноструктурного анализа (РСА) изучено влияние
предварительной обработки давлением (ОД) на особенности изменения электриче-
ского сопротивления R и структуры аморфного сплава Co67Cr7Fe4Si8B14 при нагре-
ве с постоянной скоростью до температур не выше температуры начала кристалли-
зации. ОД проведено при комнатной температуре в повторно-статическом режиме с
разным числом N циклов обработки (N = 1, 3, 5) при давлении P = 1 GPa. По дан-
ным РСА, после ОД аморфное состояние изучаемого сплава сохраняется, но тонкая
структура гало изменяется. Показано, что с ростом N циклов ОД растет упорядоче-
ние, а при нагреве в интервале 828–843 K – разупорядочение исходной аморфной
структуры сплава. Аномалии R (минимум при 497 K и резкий рост в окрестности
800–843 K), наблюдаемые на зависимости R(T) исходного аморфного сплава, после
ОД сохраняются и связаны, по-видимому, со структурными фазовыми переходами
в процессе нагревания сплава.
Ключевые слова: гидростатическое давление, аморфное состояние, структура, га-
ло, электрическое сопротивление
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