Improvement of the magnetoelectric response in NiFe2O4−Sr0.5Ba0.5Nb2O6 composites using LiNbO3 as sintering additive

Magnetoelectric (NiFe2O4) 0.3−(Sr0.5Ba0.5Nb2O6)0.7 composites with addition of LiNbO 3 as sintering additive were prepared by a classical mixed-oxide method. XRD patterns of ceramics sintered between 1000 and 1200 • C show the desired Sr 0.5 Ba 0.5 Nb 2 O 6 and NiFe 2 O 4 phases. SEM investigations confirm the 0-3 connectivity of the composite ceramics. The addition of 10 and 20 mol% LiNbO 3 improves the densi昀椀cation of the composite ceramics and leads to an increase of the size of the Sr 0.5 Ba 0.5 Nb 2 O 6 grains. Magnetic measurements show hystereses with low coercivities. Dielectric measurements were carried out depending on temperature and frequency. The samples with the LiNbO 3 addition show significantly higher resistivity values (σ DC). Magnetoelectric measurements were carried out in dependence of the magnetic DC-field, temperature, and frequency. The maximum magnetoelectric coefficient (α ME) rises with the addition of LiNbO 3 from 180 to 803 µV Oe −1 cm −1 (@900 Hz). Temperature dependent measurements show a continuously decreasing of α ME with lower temperature.