Abstract
We investigated the magnetic properties of the Pr0.5−xNdxSr0.5MnO3 (x=0, 0.1, 0.2, 0.3, 0.4, 0.5) system. Since the two end samples Pr0.5Sr0.5MnO3 and Nd0.5Sr0.5MnO3 are A-type and CE-type AFM at low temperatures, respectively, due to their different orbital ordering d(x2−y2) and d(3x2−r2)/d(3y2−r2), the magnetic structure of Pr0.5−xNdxSr0.5MnO3 is expected to be a mixture of A- and CE-type AFM. Our experiment results show that TC remains almost constant, while TN decreases dramatically as Pr3+ ions are replaced by Nd3+ ions. We suggest that this originates from the orbital ordering instability of the different magnetic structure type rather than from the ionic radius at the A-site.