Local magnetism and magnetoelectric effect in HoMnO3 studied with muon-spin relaxation

TL;DR

This study uses muon-spin relaxation to investigate the magnetic and magnetoelectric properties of HoMnO3, revealing temperature-dependent magnetic transitions and evidence of coupling between ferroelectric and magnetic domains.

Contribution

First muSR investigation of HoMnO3 showing detailed magnetic transitions and electric field effects on magnetic relaxation.

Findings

Magnetic transitions at 76 K, 38 K, and 34 K identified.

Electric field causes a small reduction in relaxation rate below 50 K.

Evidence suggests coupling between ferroelectric and magnetic domain walls.

Abstract

We present the results of muon-spin relaxation (muSR) measurements on the hexagonal manganite HoMnO3. Features in the temperature-dependent relaxation rate, lambda, correlate with the magnetic transitions at 76 K, 38 K and 34 K. The highest temperature transition, associated with the ordering of Mn3+ moments has the largest effect on lambda. The application of a static electric field of E=10^4 Vm^-1 below T=50 K causes a small reduction in lambda which is suggestive of coupling between ferroelectric and magnetic domain walls in the ordered state of the material.