Magnetic glassy behavior in ferroelectric relaxor type solid solutions: Magnetoelectric relaxor

Perovskite solid solution ceramics with compositions of 0.9Pb (Fe0.5 Nb0.5) O3 -0.1PbTi O3, 0.6Pb (Ni13 Nb23) O3 -0.4PbTi O3, and 0.6Pb (Co13 Nb23) O3 -0.4PbTi O3 were synthesized by the traditional solid state reaction method. Ferroelectric measurements revealed that these samples have well saturated polarization-electrical field loops. Dielectric measurements showed that abnormal dielectric peaks at their Curie temperature were frequency dependent. Both characteristics indicate that these samples are relaxor type ferroelectric materials. Field cooled and zero field cooled magnetization measurements revealed that the 0.6Pb (Ni13 Nb23) O3 -0.4PbTi O3 and 0.6Pb (Co13 Nb23) O3 -0.4PbTi O3 samples are paramagnetic down to 5 K, while the 0. 9Pb (Fe0.5 Nb0.5) O3 -0.1PbTi O3 sample shows an antiferromagnetic-like ordering starting from around 40 K. Furthermore, a weak ferromagnetism is observed in the 0.9Pb (Fe0.5 Nb0.5) O3 -0.1PbTi O3 sample, as evidenced by the magnetic hysteresis loop measured at 10 K. The ac susceptibility measurement of this sample showed that the peak position around 40 K is strongly dependent on frequency, indicating a glassy or relaxor type bahavior below that temperature. Therefore, relaxor type ferroelectric and magnetic 0.9Pb (Fe0.5 Nb0.5) O3 -0.1PbTi O3 is a magnetoelectric relaxor.