J.P. Maita

Superconductivity of Nb3Al

Abstract Nb 3 Al has been found to undergo a transition to the superconducting state starting at 18.8°K. This is the highest known transition temperature for any single phase binary alloy with the β-tungsten structure. A number of its electronic properties including specific heat, magnetic susceptibility and Knight Shift have been studied. It is concluded that the one-dimensional model postulated by Labbe and Friedel to explain the properties of other high temperature superconductors is inconsistent with these measurements.

Magnetic Ordering in the Rare-Earth Hexaborides

Magnetic ordering in the rare-earth hexaborides has been studied by a variety of methods, and a clear correlation with the presence of conduction electrons has been found.

Low temperature magnetic phase transition in ErCrO3

Abstract A ferromagnetic-antiferromagnetic transition was observed at 9.82 ± 0.02°K in addition to a Schottky anomaly with a maximum splitting of Δ = 13.5 ± 0.5° K .

Electronegativity and crystal field splittings in rare earth compounds

Abstract Crystal field studies in a variety of 4 f -and some 5 f electron-systems reveal a correlation between crystal field splittings, i.e. sign and charge strength of simple ligands and their electronegativities. Deviations occur in several very dilute f.c.c. noble metals, as well as noble metal compounds presumably due to the d -electron contribution and perhaps ill-defined valence states, in particular in transition metal compounds.

The occurrence of superconductivity in sulfides, selenides, tellurides of Pt-group metals☆

Superconductivity has been discovered in Pd compounds with Se and Te, in IrTe3 and in PtTe. The superconducting transition temperature of a Pd-Se alloy containing 85 to 87 at.% Pd is 0.66°K which is unusually high for its valence-electron concentration. A homogeneity range exists for the hexagonal B81-type compound PdTe and for the trigonal C6-type compound PdTe2. The results of the low temperature heat capacity measurements of PdTe and PdTe1.04 show that the large change in the transition temperature with composition is accompanied by a large change in the linear heat capacity coefficient, γ.

Superconducting, thermal and magnetic susceptibility behavior of some intermetallic compounds with the fluorite structure

Abstract AuGa2 becomes superconducting at 1.12°K. The superconducting critical temperature rises rapidly with small additions of Pd. For the composition corresponding to Au0.95Pd0.05Ga2, Tc = 1.79°K and then remains essentially constant with further increase in Pd content. The electronic contribution to the heat capacity, γ, increases in a similar manner. At Au0.95Pd0.05Ga2 the change in γ amounts to 18.4 per cent per atomic per cent Pd. All of the Au1- xPdxGa2 materials are diamagnetic and the diamagnetism decreases with increasing Pd content. The behavior of the susceptibility per gram atom,χA, at 0°K as a function of Pd content parallels the behavior of Tv, γ, and the71Ga Knight shift in these allows [2]. AuAl2 and AuIn2, becomes superconducting below 0.1°K and both show temperature independent diamagnetism, in contrast to the behavior of AuGa2.

Superconducting behavior of the system Pb(Nb1−xTax)S3

Abstract Superconducting transition temperatures in the pseudo-binary system Pb(Nb1−xTax)S3 depend on composition and thermal treatment of the samples. After annealing at relatively low temperatures a transition minimum is observed for a composition with x ≈ 0.33. The variation of the transition temperature is discussed with respect to results of specific heat measurements.

Ion pairing in Silicon

Abstract The occurrence of ion pairing in silicon is demonstrated. The pairing process is used to determine the diffusivity of lithium in silicon at low temperatures and the distance of closest approach between the ions forming the pair.