Saturation with temperature of the electrical resistivity and the CESR linewidth in TiBe2

Abstract

The electrical resistivity of TiBe2 shows anomalous behaviour at high temperature characterised by a strong reduction of the slope (d rho /dT); the authors interpret this in terms of a decoupling of the s- (or p-) like and d-like states and show that the corresponding s-d scattering resistivity rho sd tends to saturate above 300 K. The conduction electron spin resonance linewidth, which is due mainly to electron-lattice relaxation, is expected to vary like the resistivity and indeed they observe a sharp saturation of it above approximately=200 K indicating that it is more likely related to rho sd(or rho dd) rather than to the global resistivity; the saturation becomes less sharp if the residual resistivity increases, indicating a strong coupling, probably of the s-like electrons with the lattice via the local defects.