摘要
(Pb_(0.8)Ba_(0.2))[(Zn_(1/3)Nb_(2/3))_(0.7)Ti_(0.3)]O_(3)relaxor-type ferroelectric ceramics was obtained via classical solid-state reaction.The hysteresis loop results were discussed in the frame of ergodicity criterium around the characteristic ferroelectric relaxor freezing temperature.Slimer hysteresis loops were observed below the freezing temperature reflecting an ergodic relaxor behavior.Above this temperature,estimated around 223K for the studied system,larger and unsaturated like ferroelectric hysteresis loops were observed.This temperature also coincides with the slope change on maximum polarization and inflection point of remnant polarization curves.Energy storage,energy loss and efficiency values were determined in a wide temperature range.While the recoverable energy density shows relatively low values(0.23 J/cm^(3)),there are interesting behaviors for this parameter and for the efficiency,since the two physical quantities increase versus temperature and the efficiency even reaches the value of 97%.
基金
the Third World Academy of Sciences(RG/PHYS/LA No.99-050,02-225 and 05-043)
support and ICTP for financial support of Latin-American Network of Ferroelectric Materials(NT-02)
the National Program for Nanoscience and Nanotechnology of Cuba(Project No.PN211LH008-035)
the National Program for Basic Sciences of Cuba(Project No.PN223LH010-023).
