The negative magnetization and exchange bias effect in compound NdMnO3: the role of magnetic ordering of Nd3+ and Mn3+ ions.

The magnetic properties and exchange bias (EB) effect of perovskite NdMnO₃ ceramic are studied in this work. In A-type antiferromagnetic (AFM) NdMnO₃, the ordering of Nd³⁺ is caused by Mn³⁺ ferromagnetic component with antiferromagnetic coupling with each other. Interestingly, the Nd³⁺ ordering induces the Mn³⁺ spin reorientation, which explains the phenomenon of the negative magnetization at low temperature. The magnetic ordering of Nd³⁺ and Mn³⁺ ions is decisive to the EB effect. Remarkably, the positive EB effect is observed at 40 and 25 K, and both positive and negative EB effects are found at 5 K. These EB effects are relied on the cooling fields. The EB can be determined by the initial states and the coupling of Nd³⁺ ordering and Mn³⁺ ordering. The present work shows the role of magnetic ordering of Nd³⁺ and Mn³⁺ ions in regulating the EB and magnetic properties of perovskite NdMnO₃. [ABSTRACT FROM AUTHOR]