Strategies for Increasing the Néel Temperature of Magnetoelectric Fe₂TeO₆

Authors

Sai Mu, University of Nebraska-Lincoln
Kirill D. Belashchenko, University of Nebraska-LincolnFollow

Date of this Version

2015

Citation

Journal of Physics: Condensed Matter 27, 022203 (2015), 5 pp.

doi: 10.1088/0953-8984/27/2/022203

Comments

Copyright © 2015 IOP Publishing Ltd. Used by permission.

Abstract

Ways to increase the Néel temperature T_N in the magnetoelectric Fe₂TeO₆ antiferromagnet are explored with the help of first-principles calculations. Substitution of larger ions like Zr or Hf for tellurium increases the superexchange angles. The compensating O vacancies tend to form bound complexes with Zr dopants, which do not degrade the electronic band gap. T_N is estimated to increase by 15% at 12.5% Te → Zr substitution with such compensation. Substitution of N for O is favorable due to the decreased charge-transfer gap. The overall effect for N³⁻ substitution compensated by O vacancies is estimated at 3–4% T_N enhancement per 1% O → N substitution. A 1% compressive (0 0 1) epitaxial strain enhances T_N by about 6%.