Ferroelectricity in the Ferrimagnetic Phase of Fe1−xMnxV2O4**Supported by the National Basic Research Program of China under Grant Nos 2011CB921904 and 2012CB927402, the National Natural Science Foundation of China under Grant Nos 11074142 and 11021464, the Key Project of the Ministry of Education of China under Grant No 309003, and the Tsinghua TNList Cross-discipline Foundation.

Abstract

Ferroelectric and magnetic properties of Fe1−xMnxV2O4 (0 ≤ x ≤ 0.5) spinels are investigated on the basis of dielectric, polarization, and susceptibility measurements. Ferroelectric polarization is discovered in collinear ferrimagnetic and Yafet–Kittel magnetic phases for 0.1 ≤ x ≤ 0.4, which can be tuned by a magnetic field. As orbital-active Fe2+ is substituted with Mn2+, ferroelectric polarization decreases for 0 ≤ x ≤ 0.4 and disappears for x = 0.5. We propose that the two polar components in ferroelectric polarization originate from the exchange striction mechanism and the spin-current model, respectively.