Electric-field control of a magnetic phase transition in Ni₃V₂O₈

¹  Department of Physics and Astronomy, Wayne State University - Detroit, MI 48201, USA
²  Department of Physics, University of Pennsylvania - Philadelphia, PA 19104, USA

Corresponding author: glawes@wayne.edu

Received: 5 February 2009
Accepted: 17 March 2009

Abstract

We report on the electric-field tuning of a magnetic phase transition temperature (T_L) in multiferroic Ni₃V₂O₈ thin films. The simultaneous magnetic and ferroelectric transition in Ni₃V₂O₈ exhibits a clear dielectric anomaly; we monitored T_L under applied electric and magnetic fields using dielectric measurements. The transition temperature increases by 0.2 K ± 0.05 K when the sample is biased approximately 25 MV/m compared to zero bias. This electric-field control of the magnetic transition can be qualitatively understood using a mean-field model incorporating a tri-linear coupling between the magnetic order parameters and spontaneous polarization. The shape of the electric field-temperature phase boundary is consistent with the proper order parameter for the multiferroic phase in Ni₃V₂O₈ being a linear combination of the magnetic and ferroelectric correlation functions.