A muon-spin relaxation study of BiMnO3

TL;DR

This study uses muon-spin relaxation to investigate the magnetic phase transition in ferromagnetic BiMnO3, revealing critical behavior near T_C and identifying candidate muon sites through dipole calculations.

Contribution

It provides new insights into the magnetic critical behavior and muon site identification in BiMnO3 using muon-spin relaxation measurements.

Findings

Observation of muon polarization oscillations below T_C

Identification of candidate muon sites via dipole calculations

Detection of critical fluctuations near T_C

Abstract

We present the results of muon-spin relaxation measurements on ferromagnetic BiMnO3. Below T_C=98.0(1) K oscillations in the time-dependence of the muon polarization are observed, characteristic of a quasistatic magnetic field at a single muon site, allowing us to probe the critical behaviour associated with the magnetic phase transition. We are able to suggest candidate muon sites on the basis of dipole field calculations. Close to T_C, fluctuations of the Mn^3+ moments are characteristic of critical behaviour while there is a sharp crossover to a region of fast dynamic fluctuations at higher temperatures.