The linear temperature dependence of the paramagnetic resonance linewidth in the manganate perovskites and

Abstract
The temperature dependence of the static magnetic susceptibility (5 to 700 K) and that of the electron paramagnetic resonance linewidth (300 to 700 K) measured at 9.25 GHz is reported for bulk polycrystalline samples of and with negative giant magnetoresistance. For both systems, and the product increase linearly with temperature above . Following the analysis of Huber and Seehra for , it is argued that this linear temperature dependence of is most probably due to contributions from spin - phonon interaction. This result supports the recent suggestions of the importance of lattice effects in the magnetism of these oxides.