Weak-localization and Coulomb-interaction effects in hydrogen-doped Zr-Ni and Zr-Cu metallic glasses

Abstract

Measurements are described and the results presented for the temperature and magnetic field dependence of the electrical conductivity and for the magnetic susceptibility of Zr-Ni and Zr-Cu metallic glasses doped with hydrogen. Hydrogen is found to reduce both the effective electron diffusion constant and the screening of the Coulomb interaction which leads to a decrease in the conductivity, suppression of the superconducting transition temperature, and to an enhancement of the spin susceptibility at low temperatures.The relative contributions of the spin-orbit and the Maki-Thompson interaction to the magnetoresistivity are also depressed. It is shown that the theoretical models of weak localization and Coulomb interaction provide both a good qualitative and quantitative description of the anomalous temperature and field dependence of the measured properties.

The magnetic susceptibility of hydrogen-doped partially crystalline (Zr76Ni24)1−xHx metallic glasses

“…This is different from the results of the (Zr 67 Ni 33 ) 1Àx H x (Ref. [11]) and (Zr 67 Co 33 ) 1Àx H x (Ref. [12]) where hydrogen reduces both the N 0 (E F ) and S.…”

“…These results are compared with the magnetic susceptibility results for (Zr 67 Ni 33 ) 1Àx H x [11] and (Zr 67 Co 33 ) 1Àx H x [12], which also show a strong influence of the hydrogen dopant on the magnetic properties and electronic structure in Zr-3d (3d ¼ Ni, Co) metallic glasses. The room-temperature magnetic susceptibilities, w exp (300 K), of hydrogen-doped Zr-Ni and Zr-Co (and, hence, the electronic density of states at the Fermi level) decrease with increase in hydrogen concentration whereas the w exp (300 K) of the hydrogen-doped partially crystalline (Zr 76 Ni 24 ) 1Àx H x metallic glasses shows a nonmonotonic behaviour upon hydrogen doping.…”

Effect of disorder on the electrical resistivity in the partially crystalline Zr76Ni24 metallic glasses

“…Furthermore, according to XRD data [17], the modification in the chemical short-range order due to heating above the crystallisation exotherm resulting in evolution of the -Zr phase and Zr 2 Ni nanocrystalline phase plays an important role in determining the T c of the annealed samples subjected to different annealing temperatures. The values of the T c of these annealed samples are very close with the value of the T c of the Zr 2 Ni metallic glass (T c = 2.78 K) [13]. It is well-known that the T c -s decrease approximately linearly with decreasing Zr content in amorphous Zr-3d (3d = Ni, Co and Fe) alloys [26].…”

“…The increase in the T c upon annealing up to an annealing temperature below the first crystallisation exotherm in the Zr 80 Fe 20 and Zr 80 Co 20 metallic glasses has been related to the decrease in the spin-fluctuation mass enhancement parameter, λ sp . It is well known that the influence of spin fluctuations on superconductivity in Zr-3d metallic glasses decreases with increasing Zr concentration whereas at fixed Zr concentration it decreases as one move from Fe towards Ni [13,[24][25][26]. Thus, the effect of the λ sp on superconductivity in the investigated samples can be negligible.…”

“…On the other hand, the motion of electrons in disordered systems is one of the most fundamental problems in solid state physics. Both theoretical [9][10][11][12] and experimental [13][14][15][16] studies of the low temperature behaviour of electrical resistivity of disordered electronic systems have led to quantum corrections to the Boltzmann contribution. It has been shown that the diffusive motion of electrons in two-dimensional as well as in three-dimensional disordered systems entails quantum corrections to the electrical resistivity and the magnetoresistivity.…”