Ho2 O3对PZN-9PT相结构和介电性能的影响

摘要

为了研究Ho2 O3对PZN-9PT单晶相结构、相变温度及弛豫特性的影响，通过高温溶液法生长了PZN-9PT 单晶和 Ho2 O3改性PZN-9PT 单晶．采用X 射线衍射仪分析了所生长的单晶的相结构，通过测定介电常数和温度之间的关系确定了单晶的相变温度，利用洛伦兹公式和Vogel-Fulcher公式表征了Ho2 O3改性PZN-9PT单晶的弥散相变和频率色散特性．研究结果表明：PZN-9PT单晶和 Ho2 O3改性的PZN-9PT 单晶具有纯的钙钛矿结构相，PZN-9PT单晶和Ho2 O3改性的PZN-9PT单晶的居里温度接近（约为175℃），但是Ho2 O3改性的PZN-9PT单晶的三方-四方相变温度为102．3℃，其高于PZN-9PT单晶（约为90℃）．通过洛伦兹公式和Vogel-Fulcher公式拟合结果得出 Ho2 O3改性的PZN-9PT 单晶具有典型的弥散相变和频率色散特性．%In order to investigate the effect on phase structure,phase transition temperature and relaxation behavior,the PZN-9PT and Ho2 O3 modified binary PZN-9PT single crystal were grown by using the flux method.The phase analysis of the as-grown single crystal was performed using the X-ray diffraction at the room temperature.The phase transition temperatures were determined by the temperature dependence of the dielectric permittivity.The diffused phase transition and frequency dispersion of dielectric permittivity were characterized by the Loren-type law and Vogel-Fulcher law.The results revealed that the as-grown single crystal had a single phase with the perovskite structure.The Curie temperature (TC)of the as-grown single crystal was about 175 ℃.The rhombohedral to tetragonal phase transition (TR-T)ranged from 90 ℃ to 102.3 ℃ by the modification of Ho2O3. Finally,the Ho2 O3 modified PZN-9PT single crystal possessed the characterization of the diffused phase transition and frequency dispersion of dielectric permittivity by the Lorentz-type law and Vogel-Fulcher law.