BCZT无铅压电陶瓷的铁电相变  

Ferroelectric Phase Transition Character of BCZT Lead-free Piezoelectric Ceramics

作　　者：方必军[1] 刘星[1] 张震乾[1] 陈智慧[1] 丁建宁[1] 赵祥永[2] 罗豪甦[3] 

机构地区：[1]常州大学材料科学与工程学院江苏省光伏科学与工程协同创新中心,常州213164 [2]上海师范大学物理系上海师范大学光电材料与器件重点实验室,上海200234 [3]中国科学院无机功能材料与器件重点实验室,上海201800

出　　处：《材料研究学报》2017年第4期248-254,共7页Chinese Journal of Materials Research

基　　金：国家自然科学基金(51577015;11304333);江苏省产学研合作前瞻性联合研究项目(BY2014037-06);江苏省高校自然科学研究重大项目(15KJA43002);江苏高校优势学科建设工程项目~~

摘　　要：根据升温拉曼光谱和电学性能的变化研究了(Ba_(0.84)Ca_(0.15)Sr_(0.01))(Ti_(0.90)Zr_(0.09)Sn_(0.01))O_3(BCSTZS)陶瓷的铁电相变。BCSTZS陶瓷的拉曼模分为v_3(LO),v_3(TO),v_4(LO),v_2(LO,TO),v_1(TO)和v_1(LO)模。v_3(LO)和v_4(LO)模在升温至80℃后消失,表明BCSTZS的相结构从四方铁电相转变为立方顺电相。v_3(TO),v_2(LO,TO),v_1(TO)和v_1(LO)拉曼模的峰强和峰宽在室温和80℃附近出现明显的异常变化,表明在这两个温度点附近分别发生正交-四方和四方-立方铁电相变。BCSTZS陶瓷在高于居里温度(TC)时仍然存在拉曼峰,表明其内部存在极性微区。随着温度的升高谐振频率(f_r)和反谐振频率(f_a)互相接近,f_a在TC附近出现不连续变化,而应变和逆压电系数 d_(33)*( d_(33)*=S_(max)/E_(max))值随着温度的升高而逐渐降低,进一步证明发生了铁电相变。The ferroelectric phase transition characteristics of the（Ba0.84Ca0.15Sr0.01）（Ti0.90Zr0.09Sn0.01）O3（BCSTZS） ceramics were investigated by the temperature-dependent Raman spectroscopy and electrical performance. The Raman active modes of the BCSTZS ceramics can be assigned as modes such as v3（LO）, v3（TO）, v4（LO）, v2（LO,TO）, v1（TO） and v1（LO）. The modes of v3（LO） and v4（LO） disappear abruptly when the temperature extends beyond 80 ℃, indicating that the phase structure of the BCSTZS ceramics transforms from tetragonal ferroelectric（FET） phase to cubic paraelectric（PC） phase. The intensity and line width of Raman modes v3（TO）, v2（LO,TO）, v1（TO） and v1（LO） exhibit notably anomalous change around room temperature（20℃） and 80℃, showing the signal of FEO-FET（O indicating the orthorhombic ferroelectric phase） and FET-PCphase transitions. The existence of Raman active-modes, maximum strain and d33^＊values above the TCtemperatures indicates that the local polar micro-regions still retain in the cubic matrix phase. With the increase of temperature the resonant（fr） and antiresonant（fa） frequencies approach to each other, the fashows a discontinuous jump around TC, and the maximum strain and large signal d33^＊values decrease gradually, proving further the occurrence of the ferroelectric phase transition.

关 键 词：无机非金属材料 无铅压电陶瓷 铁电相变 拉曼光谱 BCSTZS 电学性能 

分 类 号：TQ174[化学工程—陶瓷工业]