Investigation of charge states and multiferroicity in Fe-doped h-YMnO3

TL;DR

This study investigates how Fe doping affects the structural, magnetic, and dielectric properties of hexagonal YMnO3, revealing mixed-valence states, suppressed antiferromagnetism, and doping-dependent magneto-electric coupling.

Contribution

It provides new insights into charge states and multiferroic behavior in Fe-doped YMnO3, highlighting the impact of Fe substitution on magnetic and dielectric properties.

Findings

Fe doping causes intra-lattice changes exceeding lattice cell variations.

Mixed-valence Mn and Fe charge states are confirmed by XANES.

Antiferromagnetic order is suppressed with Fe doping, affecting magneto-electric coupling.

Abstract

Polycrystalline YMn1-xFexO3 (YMFO_x) (0 <= x <= 0.1) compounds have been prepared in single phase and characterized by synchrotron X-ray diffraction, X-ray absorption near edge spectroscopy, magnetization, and dielectric measurements. Iron-substitution in hexagonal YMnO3 causes intra-lattice changes exceeding those of the lattice cell. XANES provide mixed-valence Mn3+/Mn4+ and Fe4+ charge states in these manganites, consistent with the observed decrease of the effective magnetic moment with Fe-doping. Magnetization M(T) evidence antiferromagnetic (AFM) ordering of the specimens with little weak ferromagnetism, and the metrices of exchange interaction suppress with Fe-doping, attributed to the lengthening of the Mn-O planar bond lengths. Dielectric {\epsilon}'(T) results showing highly doping-dependent anomaly at T_N indicate linear magneto-electric coupling.