Grain-size-induced Relaxor Ferroelectric Phase Transition in SrBi2Ta2O9 Nanoparticles
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2009年第S1期
论文作者：柯华
文章页码：20 - 23
摘 要：The transition from paraelectric phase to ferroelectric phase for SrBi2Ta2O9（SBT） nanoparticles has been investigated by high-temperature X-ray diffraction,temperature-dependent dielectric and specific heat measurements.The crystal structure of SBT nanoparticles at room temperature is orthogonal with an A21am symmetry.The high-temperature phase（>350 ℃） exhibits a tetragonal structure（I4/mmm）.There are two anomalies in all samples of SBT nanoparticles from the dielectric and specific heat curves.The high-temperature anomaly is frequency-dependent,which is a typical characteristic of relaxor ferroelectric phase transition.However,the low-temperature anomaly is heating-rate dependent,which is related to structural relaxation.These two phase transitions are accompanied with the changes in local symmetry,which is related to disordered atoms that are induced by size effects in SBT nanoparticles.
柯华
Institute for Advanced Ceramics,Harbin Institute of Technology
摘 要：The transition from paraelectric phase to ferroelectric phase for SrBi2Ta2O9（SBT） nanoparticles has been investigated by high-temperature X-ray diffraction,temperature-dependent dielectric and specific heat measurements.The crystal structure of SBT nanoparticles at room temperature is orthogonal with an A21am symmetry.The high-temperature phase（>350 ℃） exhibits a tetragonal structure（I4/mmm）.There are two anomalies in all samples of SBT nanoparticles from the dielectric and specific heat curves.The high-temperature anomaly is frequency-dependent,which is a typical characteristic of relaxor ferroelectric phase transition.However,the low-temperature anomaly is heating-rate dependent,which is related to structural relaxation.These two phase transitions are accompanied with the changes in local symmetry,which is related to disordered atoms that are induced by size effects in SBT nanoparticles.
关键词：
