Robust charge and magnetic order under electric field and current in the multiferroic LuFe(2)O(4)

TL;DR

This study investigates the effects of electric field and current on charge and magnetic order in LuFe(2)O(4), finding that observed changes are due to internal heating rather than intrinsic effects.

Contribution

The paper demonstrates that external electric fields and currents do not alter charge or magnetic order in LuFe(2)O(4), clarifying previous conflicting observations.

Findings

Electric field up to 20 kV/cm does not affect charge/magnetic structure.

Observed intensity reductions are caused by internal sample heating.

Charge and magnetic orders are robust against external electric stimuli.

Abstract

We performed elastic neutron scattering measurements on the charge- and magnetically-ordered multiferroic material LuFe(2)O(4). An external electric field along the [001] direction with strength up to 20 kV/cm applied at low temperature (~100 K) does not affect either the charge or magnetic structure. At higher temperatures (~360 K), before the transition to three-dimensional charge-ordered state, the resistivity of the sample is low, and an electric current was applied instead. A reduction of the charge and magnetic peak intensities occurs when the sample is cooled under a constant electric current. However, after calibrating the real sample temperature using its own resistance-temperature curve, we show that the actual sample temperature is higher than the thermometer readings, and the "intensity reduction" is entirely due to internal sample heating by the applied current. Our results suggest that the charge and magnetic orders in LuFe(2)O(4) are unaffected by the application of external electric field/current, and previously observed electric field/current effects can be naturally explained by internal sample heating.