Electrical resistivity of amorphous Sn-Cu alloys

The residual resistivity of amorphous Sn-Cu alloys increases with the Cu-concentration. Both positive and negative temperature coefficients are observed. The positive temperature coefficient and the transition temperature of superconductivity depend linearly on the Cu-concentration and both vanish simultaneously.     

Electrical resistivity of heusler alloys

The electrical resistivity of eight different Heusler alloys is discussed in terms of electron phonon and spin-disorder scattering. The systematics common to the alloys can be explained in the intermediate to high temperature range while the low temperature range still presents interpretation difficulties.     

Electrical resistivity and thermoelectric power of amorphous niobium-nickel alloys synthetized by vapour quenching

Thin film samples (10–20 thick) of niobium-nickel alloys in the composition range Nb-5 to 95 at % Ni were vapour quenched by R. F. sputtering onto fused quartz substrates held at a temperature of 450 K. It was found that fully glassy alloys were synthetized in the composition range Nb-30 to 85 at % Ni, 2·5 times larger than reported for splat-quenched alloys. Crystallization temperatures exhibited maxima near the eutectic composition and are comparable to those of splat-quenched materials. At room temperature, the electrical resistivity of these alloys lies between 176–210 cm, and the absolute thermoelectric power S between 2·20–2·52 V/K. On increasing the temperature from 4·2 to 775 K, up to which the amorphous alloys are stable, the resistivity of the alloy with=0·50 decreases by about 1·5%; the value of d/dT progressively increases with increasing Ni content, becoming positive at 0·50dS/dT of all alloys lies between 6–8·5×10^–3V deg^–2. The electrical behaviour of these alloys may be treated in terms of electron scattering in disordered structures assuming the nearly free-electron model, in a manner analogous to Ziman's theory of electronic transport in liquid metals.     

Superconductivity and resistivity of amorphous niobium-germanium alloys

The superconducting transition temperature, T_c, and the normal state resistivity, π, for amorphous niobium-germanium alloys were shown to vary smoothly with composition. Most notably, no anomaly was observed in the amorphous state at the composition Nb₃Ge.     

Electrical resistivity of metastable Ag-Ni alloys

We have successfully prepared solid solution metal films of Ag-Ni with Ni content to 23.4 at.%. Four-probe resistivity measurements were conducted between 2.5 and 300°K and while no anomalies of the magnetic type were observed, the temperature dependence of the resistivity indicates significant deviations from Matthiessen's rule.     

Electrical resistivity of liquid gold-silicon alloys

The electrical resistivity of liquid Au_1?xSi_x alloys was measured in the gold-rich concentration range, 0.16 ? x ? 0.40, as a function of temperature and composition. In this region the temperature coefficients of the resistivity is negative. The resistivities and temperature coefficients are compared with recent data on amorphous sputtered films; for x ? 0.31 the resistivities of the films are in agreement with those of the liquids within the accuracy of the measurements. The results can be interpreted in terms of the Ziman theory.     

Electrical resistivity and antiferromagnetism of chromium-platinum alloys

Electrical resistivity, ?, has been measured as a function of temperature, T, of Cr alloys containing 0.47, 0.93, and 1.63 at.% Pt. The onset of antiferromagnetism causes anomalies in the ? vs T curves which increase with increasing Pt concentrations. Using the criterion that at the Néel temperature, T_N, d?/dT is minimum, it has been determined that the values of T_N are (430 ± 10)K, (490 ± 5)K, and (535 ± 5)K for the above-mentioned alloys. The nature of the antiferromagnetic state and the corresponding anomalies in the electrical resistivity in the Cr-Pt system are very similar to those found in Cr-Ir solid solutions.     

On the resistivity minimum in amorphous ferromagnetic alloys

We present a theoretical approach which, taking into account the amorphous nature of the system and the correlations between nearest-neighbour magnetic ions, gives a plausible explanation of some features present in the electrical resistivity of amorphous ferromagnetic alloys with transition metals.     

Pressure dependence of the resistivity of several amorphous alloys

Measurements under hydrostatic pressure of the electrical resistance of a series of metglas alloys and one alloy of NiY have been made in the range 0–5 kbar and 77–300 K. In general the behaviour fits no general pattern, except that Metglas 2204 (BeTiZr) obeys a simple prediction of the Ziman model as found by Nagel for thermopower.     

Critical behavior of electrical resistivity in amorphous Fe-Zr alloys

Electrical resistivity (ρ) of the amorphous (a-)Fe_100−c Zr _c (c=8.5, 9.5 and 10) alloys has been measured in the temperature range 77 to 300 K, which embraces the second-order magnetic phase transition at the Curie temperature point T _c. Analysis of the resistivity data particularly in the critical region reveals that these systems have a much wider range of critical region compared to other crystalline ferromagnetic materials. The value of T _c and specific heat critical exponent, α has the same values as those determined from our earlier magnetic measurements. The value of α for all the present investigated alloys are in close agreement with the values predicted for three-dimensional (3D) Heisenberg ferromagnet systems, which gives contradiction to the earlier results on similar alloys. It is observed from the analysis that the presence of quenched disorder does not have any influence on critical behavior.     

The electrical resistivity of amorphous alloys at low temperatures

Measurements of the temperature- and magnetic field dependence of the electrical resistance of some metallic glasses are presented. The data obtained for Cu₅₇Zr₄₃, Cu₄₀Zr₆₀ and Pd₃₀Zr₇₀ demonstrate that deviations from the high temperature behaviour extrapolated to low temperatures are caused by superconducting effects. The paraconductivity which is strongly enhanced in amorphous alloys is shown to agree quite well with theoretical models. The normal state resistance does not saturate down to temperatures of about 2 K. It still exhibits a negative temperature coefficient of the resistivity.     

The pressure dependence of resistivity in amorphous copper-zirconium alloys

The variation of electrical resistance with hydrostatic pressure has been measured at room temperature for a number of amorphous Cu-Zr alloys. In each case the resistance falls to a lower value so that the volume dependence of resistance is positive. No correlation is found with the thermoelectric power of these materials and, in a detailed analysis, it is argue that for such transition metal alloys, such a simple correlation is most unlikely.     

Electrical resistivity of Co-Ga alloys at high temperatures

The rotating magnetic field method was used to investigate the temperature dependences of the electrical resistivity of Co-Ga alloys in the temperature range 800–1750C. The experimental data obtained for the liquid phase are compared with the results of a calculation made in the framework of the Faber — Ziman method as generalized by Evans to alloys of transition metals.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 61–67, December, 1978.     

Electrical resistivity of liquid binary and ternary alloys

New method of calculation of the electrical resistivity of liquid and amorphous alloys is presented. The method is based on the Morgan–Howson–S̆aub (MHS̆) model but the pseudopotentials are replaced by the scattering matrix operators. The Fermi energy is properly determined by the accurate values of the phase shifts. The model depends on a very small number of universal parameters and gives stable results. The calculated values of the resistivity agree well with available experimental data for a substantial number of binary alloys. Moreover, the results for some ternary alloys were also obtained.     

Electrical resistivity and Curie temperature of amorphous (FeNi)PC alloys

Low temperature electrical resistivity and Curie temperature of amorphous (Fe_100?xNi_x)₇₅P₁₅C₁₀ alloys (0?x?50) were studied. An application of the data to a result of a coherent potential approximation method leads to an explanation of the low temperature resistivity anomaly in terms of an electron-magnon interaction.     

Electrical resistivity in disordered,polycrsytalline FeNiTe alloys

Many disordered, crystalline and non-crystalline alloys and metallic conductors are characterized by positive as well as negative temperature coefficients of resistivity α(T) over a wide range of temperature. Experimental results are presented here to show the anomalous behaviour of resistivity with temperature in contrast to the existing theories. The anomalous electron properties can be understood in terms of an attractive interaction between conduction electrons and the localized excitations arising from structural deformity in the atomic arrangements. This scattering mechanism is used to explain the unusual departure from a linear temperature dependence above the Curie temperature (T_c) in Fe₂₈Ni₂₈Te₄₄, Fe₂₁Ni₂₂Te₅₇, Fe₁₆Ni₂₁Te₆₃ and Fe₈Ni₁₆Te₇₆ alloy.     

Calculation of the electrical resistivity of amorphous Sn-noble metal alloys

The absolute value and temperature dependence of the electrical resistivity of amorphous AuSn and CuSn alloys have been calculated on the basis of the generalized Faber-Ziman theory. The partial structure factors of the amorphous AuSn alloys were calculated for a modified microcrystallite model using the electron diffraction data for the average structure factor. The experimentally observed difference of the temperature dependence of the resistivity in the AuSn and the CuSn series is found to be largely due to the different atomic pseudopotentials for the noble metal component in these alloys.     

Electrical resistivity and magneto-resistance of very dilute Cu-Cr alloys

Measurements of the electrical resistivity from 1.5–80 K and the longitudinal magnetoresistivity from 0–95 kOe at 1.9, 4.2 and 25 K for every dilute Cr in Cu alloys are reported.