NATURAL SCIENCES

Journal of fundamental
and
applied researches

Investigation of dielectric properties of (1-x)NaNbO -xLi Bi TiO solid solutions in the low and infra-low frequency region

2014. №2, pp. 80-86

Laletin Roman A. - Ph.D. (Physics and Mathematics), Associate Professor, Volgograd State University of Architecture and Civil Engineering, 1 Akademicheskaya Str., Volgograd, 400074, Russian Federation, physic77@yandex.ru

Burkhanov Anver I. - Sc.D. (Physics and Mathematics), Professor, Volgograd State University of Architecture and Civil Engineering, 1 Akademicheskaya Str., Volgograd, 400074, Russian Federation, burkhanov@inbox.ru

Sopit Andrej V. - Ph.D. (Physics and Mathematics), Associate Professor, Volgograd State University of Architecture and Civil Engineering, 1 Akademicheskaya Str., Volgograd, 400074, Russian Federation, sandrej74@mail.ru

Bondarenko Petr V. - Ph.D. (Physics and Mathematics), Associate Professor, Volgograd State University, 100 Universitetsky Ave., Volgograd, 400062, Russian Federation, bondarenko@pisem.net

Raevskaya Svetlana I. - Ph.D. (Physics and Mathematics), Associate Professor, Southern Federal University, 105 Bolshaya Sadovaya Str., Rostov-on-Don, 344006, Russian Federation, sveta.raevskaya@mail.ru

Raevski Igor P. - Sc.D. (Physics and Mathematics), Professor, Southern Federal University, 105 Bolshaya Sadovaya Str., Rostov-on-Don, 344006, Russian Federation, igorraevsky@gmail.com

Lead-based ferroelectric ceramics has excellent ferroelectric and piezoelectric properties. However, ceramic production is associated with a high risk of environmental pollution by hazardous lead compounds. Now an active search for alternative lead-free materials with the same or similar properties is continuing. In the presented work the peculiarities of the dielectric response of one of such materials - ceramics based on niobates of alkaline metals were studied. The test samples were solid solutions with the composition (1-x)NaNbO -xLi Bi TiO , where x = 0.10 and 0.15. Measurements of dielectric permittivity and losses, as well as polarization loops were carried out at low and infra-low frequencies in a wide range of temperatures and fields. The paper presents a detailed analysis of the obtained results. It was found that in the investigated temperature interval the diffuse phase transition from the ferroelectric phase to the paraelectric one occurs. The peculiarities of the temperature and amplitude dependences of the permittivity point to relaxor-like character of behavior of the studied material. The results also indicate that the composition with x = 0.15 demonstrates essential dielectric relaxation that is explained as the relaxation of the space charge.

Key words: ferroelectric ceramics, solid solutions, relaxors, diffuse phase transition, dielectric relaxation, dielectric properties, сегнетокерамика, твердые растворы, релаксоры, размытый фазовый переход, диэлектрическая релаксация, диэлектрические свойства