Different magnetic evolution behaviors driven by multiple dynamic interactions in narrow-bandwidth manganite

Abstract

The research on magnetic regulation of manganese oxide systems with strongly correlated electron properties is increasingly active due to rich physical mechanisms and experimental phenomena. Here, Co and Cr were used to substitute the Mn-site of narrow-bandwidth half-doped Pr0.5Ca0.5MnO3 to investigate an effective alternative path to manipulate the magnetism of the PrMnO3-based manganites. The charge-exchange-type charge-ordered state of the parent material is affected significantly differently due to the varying destruction degrees of the internal spin-ordered state caused by the two elements. The competition between the ferromagnetism (FM) double-exchange and antiferromagnetism (AFM) super-exchange interactions, which initially existed only in Mn3+/4+-O-Mn3+/4+ bonds, has added Co3+-O-Mn3+/4+/Co3+ and Cr3+-O-Mn3+/4+/Cr3+ bonds, and the strength is affected by changes in various microstructure. The dynamic changes of magnetic exchange interactions result in the magnetic properties of Co-doped samples developing from the FM-AFM coexisting state to the weak FM state with the increase of doping content, while Cr-doped samples evolve from the FM state to the ferrimagnetic state. The results revealed that different magnetic states are attributed to differences in the intrinsic properties of these two elements, and the rich magnetic evolution process originates from the coexistence and competition of multiple interactions. The interesting experimental phenomena and detailed mechanism analysis contribute to the modification and application of narrow-bandwidth manganese oxides.

Keywords

• Exchange interaction
• Charge order
• Structural distortion
• Magnetic transition