Magneto-dielectric signature of Gd3+-substituted PbMg1/3Nb2/3O3 ceramics

The compound lead magnesium niobate (PMN) is a well-known relaxor ferroelectric depicting frequency-dependent dielectric maximum below similar to 250 K. The temperature and field dependences of ac/dc magnetization reveal magneto-dielectric signatures in Gd-doped PMN ceramic. The inverse magnetic susceptibility shows deviation from linear behavior on cooling, and ac susceptibility shows peak at similar to 125 K, indicating the formation of local magnetic-interacting areas, which are different from polar clusters formed at higher temperatures. However, low-temperature magnetization versus magnetic field (MH) curve described by all the samples is well elucidated by the Brillouin functions suggesting weak deviations due to some magneto-electric interaction. For higher Gd-doped PMN (x > 0.05), local interaction between the magnetic polar regions are believed to occur, where both Pb and Mg sites are substituted by Gd ions in the lattice. This result is the first strong evidence of both magnetic and polar interacting regions in this family of materials, where the temperature scales of two phenomena are different. The interaction between the two subsystems via electrostriction and magnetostriction leads to weak magneto-dielectric effect.

Automated summary

The compound lead magnesium niobate (PMN) is a relaxor ferroelectric material with frequency-dependent dielectric behavior below 250 K. Gd-doped PMN ceramics exhibit magneto-dielectric signatures, with deviation from linear magnetic susceptibility behavior and peak in ac susceptibility at around 125 K, indicating the presence of local magnetic-interacting areas. The low-temperature magnetization versus magnetic field (MH) curve can be described by Brillouin functions, suggesting weak magneto-electric interaction. The interaction between magnetic and polar regions in higher Gd-doped PMN samples (x > 0.05) provides strong evidence of their coexistence in this materials family, with different temperature scales.