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1.
Ti42.5Zr7.5Cu40Ni5Sn5 bulk metallic glass with a critical diameter of 4 mm was fabricated by the conventional copper mould casting method. The
supercooled liquid region ΔT
x, reduced glass transition temperature T
rg, γ parameter, and δ parameter of the alloy were measured to be 63.9 K, 0.561, 0.393, and 1.400, respectively, implying that the alloy has an
excellent glass-forming ability. The bulk metallic glass exhibits high compressive fracture strength of 2162 MPa with distinct
plastic strain of 0.9%. The fracture surface consists mainly of vein-like patterns, typical of bulk glassy alloys.
Supported by the Program for New Century Excellent Talents in University of China and the National Natural Science Foundation
of China (NSFC)(Grant No. 50771040) 相似文献
2.
Binary icosahedral and crystalline phases of the Zr70Pd30 alloy were obtained in crystallization from the amorphous state during heat treatment. The specific heat and electrical resistivity of the icosahedral, amorphous, and crystalline phases were measured and compared. An increase in the electronic density of states on the Fermi surface, lattice softening, and an increase in the electron-phonon coupling constant were observed to occur with decreasing structural order. Despite the high valence electron density in the icosahedral phase, where the electronic densities of states are twice those in the crystal, the electrical resistivity of the icosahedral phase is ~50 times as high. Superconductivity was observed for the first time in the icosahedral phase of a binary system of transition metal atoms, Zr70Pd30. 相似文献
3.
A.?V.?Lysenko S.?A.?Lyakhov V.?A.?Khonik M.?Yu.?Yazvitski? 《Physics of the Solid State》2009,51(2):221-225
The shear viscosity is measured under conditions of isochronous (linear) heating below the glass transition temperature of
the Pd40Cu40P20 metallic glass, which is characterized by the polymorphic crystallization into the Pd2Cu2P tetragonal phase with a lower density than the initial glass. It is shown that the rate dependence of the shear viscosity
can be interpreted as a result of the irreversible structural relaxation by analogy with the case of the previously studied
metallic glasses despite the unusual ratio of the densities of the material in noncrystalline and crystalline states. 相似文献
4.
Yu. P. Mitrofanov V. A. Khonik A. N. Vasil’ev 《Journal of Experimental and Theoretical Physics》2009,108(5):830-835
Isothermal kinetics of relaxation of the high-frequency (1.4 MHz) shear modulus during structural relaxation of Pd40Cu30Ni10P20 bulk metallic glass below the glass transition temperature is studied by an in situ method of contactless electromagnetic acoustic transformation. The kinetic law of relaxation is established. It is shown that quenching of aged samples from the supercooled liquid state leads to a decrease in the absolute value of shear modulus to below the initial value; the degree of subsequent isothermal relaxation of the modulus may be several times higher than the initial value. Possible reasons for relaxation and recovery of the shear modulus are considered. 相似文献
5.
O. P. Bobrov S. N. Laptev H. Neuhäuser V. A. Khonik K. Csach 《Physics of the Solid State》2004,46(10):1863-1867
Isochronous relaxation of tensile stresses is measured in a bulk Pd40Cu30Ni10P20 metallic glass in the initial state and after certain thermal treatments. The results of measurements are used to find the energy spectrum of irreversible structural relaxation, from which the temperature dependence of shear viscosity is then calculated. This dependence is also found independently from measurements of creep in the same glass. The calculated viscosity is shown to agree well with the experimental data. 相似文献
6.
Thin films of Sb2Te3 and (Sb2Te3)70(Bi2Te3)30 alloy and have been deposited on precleaned glass substrate by thermal evaporation technique in a vacuum of 2?×?10?6 Torr. The structural study was carried out by X-ray diffractometer, which shows that the films are polycrystalline in nature. The grain size, microstrain and dislocation density were determined. The Seebeck coefficient was determined as the ratio of the potential difference across the films to the temperature difference. The power factor for the (Sb2Te3)70 (Bi2Te3)30 and (Sb2Te3) is found to be 19.602 and 1.066 of the film of thickness 1,500 Å, respectively. The Van der-Pauw technique was used to measure the Hall coefficient at room temperature. The carrier concentration was calculated and the results were discussed. 相似文献
7.
G. E. Abrosimova N. S. Afonikova N. P. Kobelev E. L. Kolyvanov V. A. Khonik 《Physics of the Solid State》2007,49(11):2099-2103
The effect of heat treatment over the range from room temperature to 500°C on the elastic properties of a bulk amorphous Pd40Cu30Ni10P20 alloy was studied. It is shown that the increase in the shear modulus under crystallization of the alloy is two-staged and that the most significant increase in the modulus occurs at the second stage. The obtained results are compared to the x-ray structural data. It is also found that the density characteristics of the as-cast material change very slightly during the transformation from the amorphous to the crystal state, with the density decreasing slightly due to crystallization. 相似文献
8.
G. Kh. Panova N. A. Chernoplekov A. A. Shikov T. Kemény L. F. Kiss 《Physics of the Solid State》2007,49(9):1617-1622
The heat capacity of Zr70Pd30 and Zr80Pt20 icosahedral quasicrystals and their amorphous counterparts is studied in the temperature range 1.5–500 K in order to establish a correlation between the short-range atomic order and the physical properties of these compounds. A comparison of the data made it possible to reveal changes in the vibrational spectra within the low-and high-energy ranges, as well as in the density of states, superconducting characteristics, electron-phonon interaction, and anharmonicity of the lattice thermal vibrations and to calculate the main average frequencies (moments) characterizing the vibrational spectra. The lower superconducting transition temperature T c of the quasicrystals as compared to that of the amorphous counterparts can be associated with the decrease in the density of states on the Fermi surface, the hardening of the phonon spectrum, and the weakening of the electron-phonon coupling. 相似文献
9.
Yu. I. Golovin V. I. Ivolgin A. I. Tyurin V. A. Khonik 《Physics of the Solid State》2003,45(7):1267-1271
Depth-sensing (indentation) testing is used to study the characteristics of a serrated plastic flow in a Pd40Cu30Ni10P20 bulk amorphous alloy, and the boundaries between the regions of serrated and homogeneous plastic deformation are determined. 相似文献
10.
The phase transitions in Pd40Ni10Cu30P20 bulk metallic glass (BMG) have been studied under high pressure and high temperature (HP & HT) by X-ray diffaction measurements
with synchrotron radiation source. We found that the BMG underwent a phase transitions of amorphous-crystalline-amorphous
at 10 GPa upon heating. The parallel experiments were carried out at 7 GPa, while we did not observe the amorphous-crystalline-amorphous
transitions by increasing temperature. Quenching the melted BMG at 7 GPa, it was found that the phase crystallized from the
melt differed from the primary phase crystallized from the starting amorphous solid upon heating suggesting there existed
a distinct mechanism in two cases. 相似文献
11.
A. M. Vora 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2008,43(6):293-300
Theoretical computation of the pressure dependence of superconducting state parameters of a binary Ca70Mg30 metallic glass has been performed using the model potential formalism. Explicit expressions have been derived for the volume dependence of the electron-phonon coupling strength λ and the Coulomb pseudopotential μ*, considering the variation of the Fermi momentum k F and Debye temperature θD with volume. Well-known Ashcroft’s empty core model pseudopotential and five different types of the local-field correction functions, namely, Hartree, Taylor, Ichimaru-Utsumi, Farid et al. and Sarkar et al. have been used for obtaining pressure dependence of transition temperature T C and the logarithmic volume derivative Φ of the effective interaction strength N 0 V for the metallic glass superconductor. It has been obtained that T C of Ca70Mg30 metallic glass decreases rapidly with increasing pressure up to 60% decrease in the volume, for which the μ* and Φ curves show a linear nature. The superconducting phase disappears at about 60% decrease in the volume. 相似文献
12.
Magnetic anisotropies of 20 nm epitaxial film of palladium–iron alloy Pd0.92Fe0.08 grown on the (001) MgO substrate were studied. Ferromagnetic resonance (FMR) spectroscopy and vibrating sample magnetometry (VSM) were exploited to determine magnetic parameters of the film. It was found that the synthesized film reveals cubic anisotropy with tetragonal distortion. The simulated magnetic hysteresis loops, obtained utilizing the magnetic anisotropy constants taken from the FMR spectra analysis, agree well with those measured by VSM. 相似文献
13.
S. V. Khonik V. V. Sviridov N. P. Kobelev M. Yu. Yazvitskiĭ V. A. Khonik 《Physics of the Solid State》2007,49(8):1411-1416
The electrical resistances of ribbon and bulk Pd40Cu30Ni10P20 metallic glasses, whose quenching rates differ by four orders of magnitude, were precisely measured during cyclic heating. Three stages of electrical resistance relaxation are detected as the maximum heating temperature increases. The first and third stages decrease the electrical resistance, and the second stage increases it. The first stage is shown to be caused by the relaxation of deformation-induced internal stresses and not to be related to the excess free volume concentration, which differs by a factor of about 2 in the ribbon and bulk samples. The second stage reflects structural relaxation in the glass and is only partly related to its free volume. The third relaxation stage is assumed to be caused by fine precrystallization phenomena like phase separation. The effect of deformation by rolling or quenching from the temperature range of a supercooled melt on the resistance relaxation kinetics was also studied. 相似文献
14.
S. V. Khonik N. P. Kobelev V. V. Sviridov V. A. Khonik 《Physics of the Solid State》2008,50(10):1812-1818
The structural relaxation of a bulk Pd40Cu30Ni10P20 metallic glass is studied by measuring the electrical resistivity and infralow-frequency (0.05 Hz) internal friction. It is demonstrated that the structural relaxation in thermally aged samples can be restored by quenching them from a supercooled liquid state. It is found that the degree of relaxation after quenching can exceed the initial one by several times. 相似文献
15.
G. E. Abrosimova A. S. Aronin N. S. Afonikova N. P. Kobelev 《Physics of the Solid State》2010,52(9):1892-1898
The influence of plastic deformation on the structure of the Pd40Ni40P20 amorphous alloy has been investigated using X-ray diffraction and measurements of the velocity of sound. It has been revealed
that the rolling of the sample leads to a change in the structure of the amorphous phase (distortion of the first coordination
sphere) and that the structural transformations are more pronounced in the near-surface region of the sample. The rolling
also results in a decrease in the transverse velocity of sound. The observed effects decrease with time. It has been demonstrated
that the revealed effects are associated with the inelastic deformation of the amorphous alloy. 相似文献
16.
The effect of Ge additive on the physical and dielectric properties of Se75Te25 and Se85Te15 glassy alloys has been investigated. It is inferred that on adding Ge, the physical properties i.e., average coordination number, average number of constraints and average heat of atomization increase but lone pair electrons, fraction of floppy modes, electronegativity, degree of crosslinking and deviation of stoichiometry (R) decrease. The effect of Ge doping on the dielectric properties of the bulk Se75Te25 and Se85Te15 glassy alloys has also been studied in the temperature range 300–350 K for different frequencies (1 kHz–5 MHz). It is found that, with doping, the dielectric constant ε′ and dielectric loss ε″ increase with increase in temperature and decrease with increase in frequency. The role of the third element Ge, as an impurity in the two pure binary Se75Te25 and Se85Te15 glassy alloys has been discussed in terms of the nature of covalent bonding and electronegativity difference between the elements used in making the aforesaid glassy systems. 相似文献
17.
Yao-Wen Mao Cheng-Cheng Zhang Rui-Long Wang Hai-Bo Xiao Ling-Fang Xu Zheng-Cai Xia Chang-Ping Yang 《The European Physical Journal B - Condensed Matter and Complex Systems》2018,91(10):261
Two successive magnetocaloric effects consisting of inverse magnetocaloric effect around martensitic transition and negative magnetocaloric effect around magnetic transition of austenitic phase have been observed in Ni50Mn34In15Al alloy. Large inverse magnetic entropy change ΔSm ( ~ 21.3 J kg?1 K?1), small thermal and magnetic hysteresis of martensitic transition give rise of large net refrigerant capacity ( ~ 152.3 J kg?1) under a magnetic field of 50 kOe, which is comparable with that ( ~ 157.9 J kg?1) of second-order transition. The large combined magnetocaloric effects make the Ni50Mn34In15Al alloy as a promising candidate material for room temperature magnetic refrigeration. 相似文献
18.
We investigated the stability of magnetic moments in
Al69.8Pd12.1Mn18.1. This alloy exists in both, the
icosahedral (i) and the decagonal (d) quasicrystalline form.
The transition from the i- to the d-phase is achieved by a
simple heat treatment. We present the results of measurements of
the 27Al NMR-response, the dc magnetic susceptibility, and
the low-temperature specific heat of both phases. In the
icosahedral compound, the majority of the Mn ions carries a
magnetic moment. Their number is reduced by approximately a factor
of two by transforming the alloy to its decagonal variety. For
both compounds, we have indications for two different local
environments of the Al nuclei. The first reflects a low density of
states of conduction electrons and a weak coupling of the Al
nuclei to the Mn-moments. The second type of environment implies a
large d-electron density of states at the Fermi level and a
strong coupling to the magnetic Mn moments. Spin-glass freezing
transitions are observed at Tdecaf=12 K for the
decagonal, and Ticof=19 K for the icosahedral phase. 相似文献
19.
Glassy LiPO3/crystalline Al2O3 and glassy LiPO3/crystalline ZrO2 (0–12.5 vol.% of oxide fillers) composite solid electrolytes have been prepared by glass matrix softening. Their thermal and transport properties have been investigated by differential scanning calorimetry (DSC) and impedance spectroscopy methods. The addition of ZrO2 leads to a decrease in the crystallization temperature of LiPO3 glass. It was found that the conductivity behavior depends on the nature of the dispersed addition. In the case of the Al2O3 addition, the increase in the electrical conductivity is observed. The ionic conductivity of the LiPO3/10% Al2O3 composite reaches 5.8 × 10?8 S/cm at room temperature. In contrast, the conductivity in the LiPO3/ZrO2 composite system decreases. 相似文献