Electric-field switch of magnetization in BaTiO3–Na0.5Bi0.5TiO3–NiFe2O4 composite

We demonstrate magnetoelectric coupling effect in (80BaTiO3–20Na0.5Bi0.5TiO3)–NiFe2O4, abbreviated as (BTO–NBT)–NFO, synthesized by the solid-state sintering method. The dielectric, magnetic and magnetoelectric behaviors of (100–x) (BTO–NBT)–xNFO (x = 35, 45, 55) particulate composites are investigated. The composites show coexistence of dielectric properties and magnetic behaviors. A reversible, room temperature magnetization switch determined by an electric field in (100–x) (BTO–NBT)–xNFO (x = 35, 45, 55) composites is observed. This effect of electric-field-controlled magnetization is believed to originate from the combination of strain-induced and charge-mediated coupling. Magnetoelectric relaxation occurs when the magnetization is switched electrically, it is especially pronounced for the composite with x = 45 and 55, which could be attributed to the increase in the conductivity. A maximal converse magnetoelectric coefficient of 3.736 Oe cm V−1 is obtained for 65(BTO–NBT)–35NFO modulated by an electric field of 2 × 106 V m−1 at a bias field of 1000 G. Such electrically control of magnetization switch shows great promises for the read and write operations to be performed using only electric field for writing and small magnetic field for reading.