CAJ | 학술논문

应用显微拉曼技术对弛豫型铁电体0.67 PbMg1/3Nb2/3O3-0.33 PbTiO3 (0.67 PMN-0.33 PT)的偏振拉曼光谱随温度变化的研究表明,在-196 到 600 °C温度范围内0.67 PMN-0.33 PT存在两次相变:三方到四方(R-T)相变和四方到立方(T-C)相变.R-T相变的特征是106 cm-1软模(-196°C时) 随温度的升高而湮没到80 cm-1"静态"模式中.依照群论分析,0.67 PMN-0.33 PT的80 cm-1 和 106 cm-1 (-196 ℃时)两个模式分别为E(1TO) 和 A1(1TO)模.文章对三方相的对称结构(C3v点群)在背向散射配置下不同偏振方向的拉曼散射效率进行了计算.计算结果表明晶体中的A1(1TO) 和E(1TO)模式能够通过使用不同的散射配置进行识别.理论计算和实验结果相比较得到了很好的吻合.
응용현미랍만기술대이예형철전체0.67 PbMg1/3Nb2/3O3-0.33 PbTiO3 (0.67 PMN-0.33 PT)적편진랍만광보수온도변화적연구표명,재-196 도 600 °C온도범위내0.67 PMN-0.33 PT존재량차상변:삼방도사방(R-T)상변화사방도립방(T-C)상변.R-T상변적특정시106 cm-1연모(-196°C시) 수온도적승고이인몰도80 cm-1"정태"모식중.의조군론분석,0.67 PMN-0.33 PT적80 cm-1 화 106 cm-1 (-196 ℃시)량개모식분별위E(1TO) 화 A1(1TO)모.문장대삼방상적대칭결구(C3v점군)재배향산사배치하불동편진방향적랍만산사효솔진행료계산.계산결과표명정체중적A1(1TO) 화E(1TO)모식능구통과사용불동적산사배치진행식별.이론계산화실험결과상비교득도료흔호적문합.
Polarized Raman spectra of ferroelectric relaxor 0.67Pb(Mg1/3Nb2/3)O3 - 0.33 PbTiO3 (0.67 PMN-0.33 PT) single crystals have been systematically investigated in a wide temperature range from -196 to 600 ℃ by micro-Raman scattering technique. The two structural phase transitions in the crystal were clearly revealed. One is the rhombohedral-tetragonal (R-T) phase transition, other one is the tetragonal-cubic (T-C) phase transition. The characteristic of the R-T phase transition is the soft mode at 106 cm-1 (at -196℃) which merges to the "static" mode at 80 cm-1 as temperature increases. According to the analysis of the group theory, the two modes at about 80 cm-1 and 106 cm-1 (at -196℃), respectively, are attributed to E(1TO) and A1(1TO) in the 0.67PMN-0.33PT. Raman scattering efficiencies of the rhombohedral symmetry structure (C3v point group) for the crystal in backscattering geometry with different polarization directions are calculated. The analytic results indicate that A1(1TO) and E(1TO) modes in the crystal can be identified by using different scattering geometry. A comparison of experimental results with theoretical predictions shows satisfactory agreement.