Electron spin resonance in heavily doped TMMC : Cu

Abstract

We report ESR measurements in the one-dimensional Heisenberg paramagnet (CH3)4NMn1-xCuxCl3 for x ranging between 0 and 0.5. The room temperature results show a maximum of the linewidth for a concentration x ~ 0.25, in agreement with the altered diffusion model, with the notable exception of the magic angle orientation. A lineshift towards low fields is observed in strongly doped samples. At lower températures, ESR is also modified by the impurities, in accordance with the réduction of the short time effects and the enhancement of the diffusive contribution.