共查询到20条相似文献,搜索用时 15 毫秒
1.
G. E. Abrosimova A. S. Aronin S. V. Dobatkin I. I. Zver’kova D. V. Matveev O. G. Rybchenko E. V. Tat’yanin 《Physics of the Solid State》2007,49(6):1034-1039
The structural evolution of an amorphous Fe80B20 alloy subjected to severe plastic deformation at room temperature or at 200°C was studied. Deformation leads to the formation of α-Fe nanocrystals in an amorphous phase. After room-temperature deformation, nanocrystals are localized in shear bands. After deformation at 200°C, the nanocrystal distribution over the alloy is more uniform. Possible causes of the crystallization of the amorphous phase during severe plastic deformation are discussed. 相似文献
2.
The optical properties of Fe78Si10B12 ferromagnetic alloy in amorphous, crystalline, and intermediate structural states have been investigated by ellipsometry
in the spectral range of 0.22–18 μm. It is established that alloy crystallization leads to a significant change in the optical
constants and the frequency dependences of the dielectric functions calculated based on these optical constants. The structural
reconstruction under heat treatment leads to an increase in the intensity and shift of interband absorption bands. The plasma
and relaxation frequencies of conduction electrons are determined; their numerical values also depend on the degree of atomic
ordering. 相似文献
3.
Glass-forming ability (GFA) and thermal stability of Fe62Nb8B30, Fe62Nb6Zr2B30 and Fe72Zr8B20 at % amorphous alloys were investigated by calorimetric (DSC and DTA) measurements. The crystallization kinetics was studied
by DSC in the mode of continuous versus linear heating and it was found that both the glass transition temperature, T
g
, and the crystallization peak temperature, T
p
, display strong dependence on the heating rate. The partial replacement of Nb by Zr leads to lower T
g
and T
x
temperatures and causes a decrease of the supercooled liquid region. JMA analysis of isothermal transformation data measured
between T
g
and T
x
suggests that the crystallization of the Fe62Nb8B30 and Fe62Nb6Zr2B30 amorphous alloys take place by three-dimensional growth with constant nucleation rate. Nb enhances the precipitation of the
metastable Fe23B6 phase and stabilizes it up to the third crystallization stage. Zr addition increases the lattice constant of Fe23B6 and, at the same time, decreases the grain size. 相似文献
4.
The short-range order around boron, aluminum, and iron atoms in Fe75B25 and Fe70Al5B25 amorphous alloys has been studied by 11B and 27Al nuclear magnetic resonance at 4.2 K and 57Fe Mössbauer spectroscopy at 87 and 295 K. The average magnetic moment of iron atoms μ(Fe) in these alloys has been measured by a vibrating sample magnetometer. It has been revealed that the substitution of aluminum atoms for iron atoms does not disturb μ(Fe) in the Fe70Al5B25 alloy, gives rise to an additional contribution to the 11B NMR spectrum in the low-frequency range, and shifts maxima of the distribution of hyperfine fields at the 57Fe nuclei. In the Fe70Al5B25 amorphous alloy, the aluminum atoms substitute for iron atoms in the nearest coordination shells of boron and iron atoms. This alloy consists of nanoclusters in which boron and iron atoms have a short-range order of the tetragonal Fe3B phase type. 相似文献
5.
N. A. Shurygina A. M. Glezer I. E. Permyakova E. N. Blinova 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(1):44-50
The kinetics of primary crystallization and the effect of structural parameters of the precipitating nanocrystalline α-phase
Fe-Si on changes in microhardness, coercive force, and saturation magnetization in an amorphous Finemet-type 5BDSR alloy (Fe78.5Si13.5B9Nb3Cu1) obtained by melt quenching are studied. It is found that both an increase in bulk density and an increase in the average
nanoparticle size contribute to the hardening of the amorphous/nanocrystalline alloy. 相似文献
6.
I. E. Permyakova A. M. Glezer E. S. Savchenko I. V. Shchetinin 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(11):1310-1316
Variations in the magnetic characteristics (specific saturation magnetization and coercive force) of Co–Fe–Cr–Si–B amorphous alloy (AA) are studied after high-pressure torsion (HPT) and heat treatment. The behavior of AA magnetic properties is analyzed with respect to structural transformations caused by external actions. The corrosion resistance of AA upon transitioning from an amorphous to a crystalline state is investigated. The established optimum annealing and HPT conditions yield a satisfactory combination of the magnetic properties and corrosion resistance of the investigated alloy. 相似文献
7.
This paper presents the results of investigation on the influence of temperature on magnetoelastic characteristics of the
two ring-shaped cores, made of Fe70Ni8Si10B12 amorphous alloy. The cores were annealed for 1 h at 350 and 400°C, respectively. The compressive force F was applied perpendicular to the direction of the magnetizing field H in the sample. Special cylindrical backing enables application of the uniform compressive stress σ to the wound ring sample. A resistive furnace heated the experimental set-up. Results presented in the paper indicate a significant
influence of the temperature on the magnetoelastic characteristics of Fe70Ni8Si10B12 amorphous alloy. Information about the magnetoelastic characteristics of this material may be useful in the magnetoelastic
sensor development. Also this will create new possibilities in the development of physical model of magnetoelastic effect.
相似文献
8.
S. V. Komogortsev R. S. Iskhakov P. A. Kuznetsov A. I. Belyaeva G. N. Bondarenko L. A. Chekanova 《Physics of the Solid State》2010,52(11):2287-2290
The structural properties and parameters of ferromagnetic resonance have been studied for Fe73.5CuNb3Si13.5B9 nanocrystalline alloys produced from the initial amorphous state via annealing under different conditions. The dependence
of the linewidth of the ferromagnetic resonance on the grain size ΔH ∼ D
6 has been found. The result is discussed within the framework of the random magnetic anisotropy model. 相似文献
9.
Marcel Miglierini Tomáš Kaňuch Tibor Krenický Ivan Škorvánek 《Czechoslovak Journal of Physics》2004,54(4):73-76
The influence of different degrees of crystallinity on the magnetic behaviour of heat-treated nanocrystalline Fe76Mo8Cu1B15 alloy has been investigated using a combination of Mössbauer spectrometry and magnetic measurements. The evolution of magnetically active regions and their growth with rising contents of nanocrystals are followed by distributions of hyperfine interactions. Combined electric quadrupole and magnetic dipole interactions corresponding to non-magnetic and magnetic regions inside the amorphous phase, respectively, were revealed. A deterioration of the soft-magnetic properties takes place for the samples exhibiting low fraction of crystallinity. The very good soft-magnetic behaviour is regained for the samples where the primary crystallization process is almost finished. 相似文献
10.
A theoretical analysis of small-angle neutron scattering is performed for the Fe65Ni35 alloy at a temperature T=0.9T C =450 K. The results obtained indicate the existence of long-wavelength magnetic excitations that do not correspond to spin waves of the Holstein-Primakoff type. The possible nature of these excitations is discussed. 相似文献
11.
V. I. Betekhtin P. N. Butenko V. L. Hilarov A. G. Kadomtsev V. E. Korsukov M. M. Korsukova B. A. Obidov 《Physics of the Solid State》2008,50(10):1875-1881
The effect of hydrostatic pressure and uniaxial compression on the relief of an amorphous Fe77Ni1Si9B13 alloy ribbon surface was studied using scanning tunneling and atomic-force microscopy. The fracture surfaces of samples were also studied. It is found that both the initial surfaces and the surfaces of samples subjected to hydrostatic compression or tension, as well as fracture surfaces, are fractal or multifractal, but their fractality parameters are different. Hydrostatic pressure decreases the surface roughness and the average fractal dimension of the surface on both sides of the ribbons. The dependence of the surface fractal characteristics on tension is more complex. Prior to the occurrence of a “critical event” on the surface (formation of a deformation band or a through crack), the Hölder index and the half-width of the singularity spectrum decrease. The correlation is discussed between the fractal characteristics of the ribbon surface and those of a fracture surface, and the role of an excess free volume in the initiation of fracture of amorphous alloys is analyzed. 相似文献
12.
“Zero field”-Mössbauer and magnetization measurements have been performed on an amorphous Fe76Mo8Cu1B15 alloy in the temperature range of (10-340) K. The room-temperature Mössbauer spectrum exhibits magnetic dipole and electric quadrupole interactions. At approximately 306 K, the magnetic interactions vanish and the alloy shows fully paramagnetic behavior. On the other hand, the relative representation of paramagnetic component becomes weak with decreasing temperature and below 220 K the magnetic dipole interactions prevail. Below this temperature an anomaly in the low-temperature dependencies of ac susceptibility and of magnetization, measured during cooling the specimen from 340 K down to 20 K is observed. The anomaly on the magnetization curve vanishes in the field of 200 Oe. 相似文献
13.
A structural model of the cubic paraelectric phase of a Fe3B7O13Br crystal belonging to the boracite family has been developed using the data obtained by single-crystal X-ray diffraction
with due regard for the results of extended X-ray absorption fine structure (EXAFS) spectroscopy. It has been shown that the
best agreement between the data obtained by these two methods is achieved within a model assuming a disorder in the arrangement
of both the Fe and Br atoms and a high degree of correlation of their displacements. It has been found that, during the phase
transition from the rhombohedral ferroelectric phase to the cubic paraelectric phase, no significant transformation of the
structure is observed on a local level. In this case, a change in the macroscopic symmetry occurs predominantly as a result
of the variation in the set of possible spatial orientations of stable structural fragments, which is characteristic of order-disorder
phase transitions. 相似文献
14.
P. Kollu L. Jin K.W. Kim S.S. Yoon C.G. Kim 《Applied Physics A: Materials Science & Processing》2008,90(3):533-536
A novel asymmetric giant magneto impedance (AGMI) sensor was developed and the performance of the sensor was carefully studied.
This one dimensional sensor can be further developed as a two-dimensional compass that can be used for navigational purposes.
We used commercial Metglas 2714A ribbon. The sensor uses Co66Fe4Si15B15 ribbon as a sensing element.
The results showed for high sensitivity and resolution. The GMI sensor consists of a crystal oscillator voltage to current
converter for providing the current to the sample, a differential amplifier, successive amplifier stages, multiplier, and
cascaded low-pass filters. The observed sensitivity was 25 V/Oe. Angle sensitivity was found to be 2 mV/degree. Our sensor
showed excellent linearity when compared with previous sensors [13, 14]. These sensors require dc bias coils and two sensor
elements to attain good linearity.
PACS 85.75.Ss; 85.70.Ay; 85.70.-w; 85.75.-d; 75.30.Gw; 75.50.Kj; 75.90.+w 相似文献
15.
To analyze the origin of the magnetic enhancement of Fe-Ni alloy, the electronicconfigurations and magnetic properties were investigated using density functional theorybased on the first-principle. The supercell (5 × 1 × 1) of Fe,Fe9Ni1 and Fe8Ni2 were constructed. Thedefect formation energy, band structure, density of states and electron density differencewere calculated. The results showed that Ni doping changed the electronic configuration ofFe atoms, resulting in the enhancement of spin polarization of Fe and the larger Bohrmagnetic moment in Fe-Ni alloys (Fe9Ni1). The results showed thatthe charge transfer and the atomic spacing between Fe atoms and the dopant Ni atoms playedan important role in determination of magnetic moment. The value of Fe supercell(5 × 1 × 1), Fe9Ni1 and Fe8Ni2 were 23.14,23.34 and 22.61μ B, respectively. 相似文献
16.
Zhi-Gang Wang 《The European Physical Journal C - Particles and Fields》2008,56(2):181-187
In this article, we calculate the strong coupling constants gBs0Bsη and gBs1B*sη with the light-cone QCD sum rules. Then we take into account the small η–π0 transition matrix according to Dashen’s theorem, and we obtain the small decay widths for the isospin violation processes
Bs0→Bsη→Bsπ0 and Bs1→Bs
*η→Bs
*π0. We can search the strange-bottomed (0+,1+) mesons Bs0 and Bs1 in the invariant Bsπ0 and B*
sπ0 mass distributions, respectively.
PACS 12.38.Lg; 13.25.Hw; 14.40.Nd 相似文献
17.
J.L. Fu D.Q. Gao Y. Xu D.S. Xue 《Applied Physics A: Materials Science & Processing》2008,90(1):119-121
Fe-rich Fe96-xZrxB4 (0≤x≤7) nanowires were first prepared by electrodepositing into anodic aluminum oxide templates. Transmission electron microscope analysis shows that the nanowires are uniform and are about 100 nm in diameter with an aspect ratio of around 75. The broad peaks of X-ray diffraction and the Mössbauer spectrum indicate that the Fe96-xZrxB4 nanowires are composed of α-Fe-like and Zr-rich FeZrB phases. Selected area electro diffraction results also indicate that the structure of Fe89Zr7B4 nanowires is amorphous. A vibrating sample magnetometer is employed to study the magnetic properties of nanowire arrays at room temperature. The coercivity of nanowire arrays in parallel to the wire axis decreases with increasing Zr content. 相似文献
18.
The chemical structure of Fe78B13Si9 alloy in the solid and liquid states and local atomic environment are studied in situ by X-ray photoelectron spectroscopy (XPS). The chemical bonds between elements in the melt are analyzed during a temperature increase. Two temperature regions are identified. The liquid surface in the first temperature region is shown to contain clusters of Fe-Si and (Fe-O x )-Si types. In the second one, clusters of Fe-B and (Fe-O x )-B types dominate. It is impossible to determine the composition of the clusters definitively using XPS data only. A jump-like change in the composition of the surface layers of the melt is detected, which is interpreted as structural transformations within the liquid state. 相似文献
19.
The magnetic and electrical properties of metallic glasses with the general formula Fe85-xCoxB15 were investigated over a large temperature range to study their concentration-dependent physical parameters. All of the samples investigated (x=17,21,30, and 40) were soft ferromagnets with coercive fields Hc1 Oe and high Curie temperatures slightly above 1200 K. The temperature-dependent magnetization behaved irregularly, and exhibited hysteresis during heating and subsequent cooling through the Curie temperature. The variation of the magnetization with temperature demonstrates that one or more phase transformations (crystallization) occurred in the course of the heating. The electrical resistivities exhibited positive temperature coefficients and minima at temperatures below 50 K. We did not observe a nonmonotonic variation of the magnetic and electrical properties with a monotonic change of the Fe85-xCoxB15 composition that would correlate with the earlier proposed formation of strong nanoclusters in the vicinity of particular stoichiometrically close Fe:Co ratios. The good soft magnetic characteristics make the Fe85-xCoxB15 metal glasses promising candidates for engineering materials in inductive applications. PACS 71.23.Cq; 75.75.+a 相似文献
20.
E. E. Shalyguina I. Škorvánek P. Švec V. A. Mel’nikov N. M. Abrosimova 《Journal of Experimental and Theoretical Physics》2004,99(3):544-551
Inverted hysteresis loops were observed for the first time in the near-surface layers of heterogeneous (nanocrystalline/amorphous) Fe81Nb7B12 alloys. In particular, a negative residual magnetization is observed when a positive magnetic field applied in the sample plane is decreased to zero. The inverted hysteresis is qualitatively explained within the framework of a two-phase model, according to which the heterogeneous alloys contain two dissimilar phases exhibiting uniaxial magnetic anisotropy and featuring antiferromagnetic exchange interaction. 相似文献