X-Ray Investigations of the Intermetallic Phases CaCd1-x Tlx and Caln1-x Tlx and Knight Shift Measurements of 205Tl- and 113Cd-NMR in the System CaCd1-x Tlx

Abstract

The quasibinary systems CaCd1-xTlx and CaIn1-xTlx- form continuous series of solid solutions for all concentrations x: 0 ≦ x ≦ 1. All alloys of both systems crystallize with space group Oh1-PmSm and one formula unit per unit cell (CsCl-type structure). Considerable deviations from Vegard’s law occur for CaCd1-x Tlx, while they are negligible for CaIn1-x Tlx. No sign for the appearance of superstructures was found in either system after equilibrating them at 300 °C for two hours. In the system CaCd1-xTlx the Knight shift Ks of the 205Tl- and 113Cd-NMR was measured at room temperature as a function of x. Saturated Tl(CH3CO2)- and Cd(NO3)2 solutions served as reference samples. The Knight shift of the 205Tl-resonance increases remarkably with increasing concentration x, whereas the Knight shift of the 113Cd-NMR decreases slightly with increasing x. No simple qualitative explanation is found for Ks(Tl) =f(x) and Ks(Cd) =f(x)