摘要
为了从晶格原子振动方面进一步弄清ZrO2的t→m相变本质,测定了10%CeO2(in mole)-ZrO2(简写为10 ce)的Raman光谱。从室温到液氮温度(77 K)的Raman光谱表明,降温过程中大约在153 K发生了t→m相变。相变过程中,某些Raman谱峰的波数(频率)和半高宽发生了跃变:640 cm-1B1g,模向低波数移动,320 cm-1Blg模和460 cm-1Eg模向高波数移动;640 cm-1B1g和320 cm-1Blg峰的半高宽亦有明显变化。实验结果表明:体现原子位移的某些Raman活性模波数跃变的实质是相变声子模的凝聚所致。另外,讨论了10Ce的t相晶格动力学,根据文献提供的Zr,O原子振动位移矢量绘制出了t相6个Raman活性模的晶格原子简正振动图像。
The t→m phase transition (PT) of ZrO2 was investigated from the aspect of lattice vibration by measuring the Raman spectra of 10%CeO2(in mole) - ZrO2(10Ce) at different temperatures from ambient to liquid nitrogen temperatures. The Raman spectra show that the t→m PT suddenly occurs at about 153 K during the course of decreasing temperature. In the t→m PT, the full width at half maximum (FWHM) and the wave number (frequency) of some Raman bands abruptly change in a way that the 640 cm-1 B1g mode shifts toward a lower wave number and the 320 cm-1 B1g and 460 cm-1 Eg modes toward a higher wave number. The experimental results show that the abrupt changes of some Raman-active modes indicating the atomic displacement is virtually due to the condensation of phonon modes in the t→m PT. In addition, the lattice vibration of t-phase was discussed and the images of vibration displacement of six Raman-active modes for t-phase were presented according to the placement eigenvectors of phonons provided by the reference.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2002年第6期755-760,共6页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金资助项目(59772012)。
