Magnetic properties and electron spin resonance of charge ordering manganite Y0.5Ca0.5MnO3

We report the magnetization and electron spin resonance study on charge-ordering (CO) manganite Y0.5Ca0.5MnO3 (YCMO) across the charge-ordering transition temperature TCO down to the antiferromagnetic ordering transition temperature TN. The transition temperatures of TCO and TN are observed at 275 and 125 K, respectively. The observed large decrease in the linewidth from TN to TCO can be explained in terms of motional narrowing caused by the hopping of the Jahn-Teller (JT) polarons. Below TCO the g-value is almost constant, suggesting the weakening of orbital order in the compound of YCMO.