6533b832fe1ef96bd129ab52

RESEARCH PRODUCT

Epitaxial Films of Relaxor Ferroelectric PbMg1/3Nb2/3O3in Strong Electric Fields

subject

description

Epitaxial thin films of perovskite relaxor ferroelectric PbMg 1/3 Nb 2/3 O 3 were grown on MgO (001) substrates by pulsed laser deposition using La 0.5 Sr 0.5 CoO 3 bottom electrode layers. Dielectric response of the films was experimentally studied as a function of temperature and frequency in a broad range of amplitudes of ac electric field (to 10 MV/m) and magnitudes of dc electric field (to 50 MV/m). At small fields, a glass-like behavior was observed. With increasing magnitude of the dc field, an onset of a polar state was detected. The orientation of the polar clusters along the direction of the field and fluctuations of the direction of their dipole moments were suggested to determine the response in the polar state. With increasing amplitude of the ac field, indications of possible onset of the polar phase were found, too. Also for such a polar phase, both orientational and fluctuational mechanisms could contribute to the response.