Magnetic structures and magnetoelastic coupling of Fe-doped hexagonal manganites LuMn1-xFexO3 (0 < x < 0.3)

TL;DR

This study investigates how Fe-doping affects the magnetic and crystal structures of hexagonal LuMnO3, revealing increased Néel temperatures, complex spin configurations, and composition-dependent reorientations, advancing understanding of multiferroic materials.

Contribution

It provides detailed insights into the magnetic structures and phase diagram of Fe-doped LuMnO3, highlighting the role of Fe-doping in tuning magnetic properties and spin configurations.

Findings

Néel temperature increases with Fe-doping

Magnetic ground state involves mixed spin representations

Fe-doping induces composition-dependent spin reorientations

Abstract

We have studied the crystal and magnetic structures of Fe-doped hexagonal manganites LuMn1-xFexO3 (x = 0, 0.1, 0.2, and 0.3) by using bulk magnetization and neutron powder diffraction methods. The samples crystalize consistently in a hexagonal structure and maintain the space group P63cm from 2 to 300 K. The N\'eel temperature TN increases continuously with increasing Fe-doping. In contrast to a single {\Gamma}4 representation in LuMnO3, the magnetic ground state of the Fe-doped samples can only be described with a spin configuration described by a mixture of {\Gamma}3 (P63'cm') and {\Gamma}4 (P63'c'm) representations, whose contributions have been quantitatively estimated. The drastic effect of Fe-doping is highlighted by composition-dependent spin reorientations. A phase diagram of the entire composition series is proposed based on the present results and those reported in literature. Our result demonstrates the importance of tailoring compositions in increasing magnetic transition temperatures of multiferroic systems.