The magnetic ordering in the PrNd_x Sr_0.5 MnO₃ system

National High Magnetic Field Laboratory, University of Science and Technology of China, Hefei 230026, PRC

Corresponding author: pili@ustc.edu.cn

Received: 2 March 2007
Accepted: 29 June 2007

Abstract

We investigated the magnetic properties of the PrNd_xSr_0.5MnO₃ (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) system. Since the two end samples Pr_0.5Sr_0.5MnO₃ and Nd_0.5Sr_0.5MnO₃ are A-type and CE-type AFM at low temperatures, respectively, due to their different orbital ordering and /, the magnetic structure of PrNd_xSr_0.5MnO₃ is expected to be a mixture of A- and CE-type AFM. Our experiment results show that T_C remains almost constant, while T_N 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.