Dielectric and Ferroelectric Properties of Ba4Gd2Fe2Nb8O30 with filled tungsten-bronze structure
Polycrystalline sample of Ba4Gd2Fe2Nb8O30 ceramics were prepared by a high temperature solid-state reaction technique. The structure and dielectric properties as well as the behavior of ferroelectric phase transition have been investigated. The dielectric spectra are characterized in wide frequency (40Hz-1MHz) and temperature (25℃-600℃). At 1MHz, the room temperature dielectric constant of Ba4Gd2Fe2Nb8O30 ceramic is 160 together with dielectric loss of 0.054. Two dielectric abnormalities were detected at the temperature dependence of dielectric spectra in low and high temperature ranges, respectively. The low temperature peak (145℃) is frequency independence, while the higher temperature (300℃-600℃) one is extremely high relaxorlike, with very strong frequency dispersion. The high temperature peak was not relaxor ferroelectric but an oxygen defect induced dielectric abnormity, while the low temperature one was proposed to the ferroelectricparaelectric phase transition. The ferroelectric nature of the present materials is confirmed by the P-E hysteresis loop, with 2 Prof 1.5μC/cm2.
ferroelectric TB dielectric properties
Chun Chun Li Liang Fang Xi Yang Peng Chang Zheng Hu
State Key Laboratory of Advanced Technology forMaterials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,PR China Key Laboratory of Nonferrous Materials and NewProcessing Technology,Ministry of Education ,Guilin University of Tech
国际会议
西安
英文
176-179
2009-08-23（万方平台首次上网日期，不代表论文的发表时间）