Precursory Softening of Polar Mode in Isotope-Exchanged Paraelectric Strontium Titanate Studied by Raman Scattering
Precursory Softening of Polar Mode in Isotope-Exchanged Paraelectric Strontium Titanate Studied by Raman Scattering
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DOI：
10.1080/00150190600738196
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发表时间：
2006-08
期刊：
影响因子：
0.8
通讯作者：
H. Taniguchi;M. Takesada;M. Itoh;T. Yagi
中科院分区：
文献类型：
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作者：
H. Taniguchi;M. Takesada;M. Itoh;T. Yagi
量子顺电SrTiO_3通过16 O交换其同位素18 O而显示铁电性。对交换速率低于临界交换速率的SrTi（O0.321618O0.68）3进行了拉曼散射实验。顺电相铁电体软模的拉曼光谱清楚地表明了由18 O-交换引起的局域介电断裂。SrTi（O0.321618O0.68）3中软模的温度依赖性表明在铁电相开始之前发生了局部铁电区。系统的不均匀性导致18 O交换SrTiO 3中软模的不均匀软化。
Quantum paraelectric SrTiO3 shows the ferroelectricity by the exchange of 16O for its isotope 18O. Raman scattering experiment is performed on the isotopically exchanged SrTi(O0.32 16 18O0.68)3 whose exchange rate is just below the critical exchange rate. Raman spectrum of ferroelectric soft mode in the paraelectric phase clearly indicates local symmetry-breaking induced by the 18O-exchange. The temperature dependence of the soft mode in SrTi(O0.32 16 18O0.68)3 suggests the occurrence of local ferroelectric region before the onset of the ferroelectric phase. The inhomogeneity of the system induces the inhomogeneous softening of the soft mode in 18O-exchanged SrTiO3.