The Synthesis of La1-xNaxTiO3 under High-Pressure and High-Temperature and Its Spectra Study
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摘要: 利用高压高温合成方法合成了具有混合价态的钙钛矿氧化物La1-xNaxTiO3。XRD测量表明,样品为畸变的立方钙钛矿结构,晶胞体积随x的增加而减小。XPS和EPR表明,x=0.3,0.4样品中的Ti离子为+3、+4混合价,并且存在A位离子空位。IR测量表明,Ti-O键伸缩振动频率随x增加而增加。高压高温可以改变Ti离子的价态。Abstract: Perovskite oxides of La1-xNaxTiO3 with mixed valence were synthesized under high-pressure and high-temperature. XRD measurement shows that the samples belong to distorted cubic perovskite structure. Volumes of samples decrease as x increases. XPS and EPR measurements indicate that Ti ions are mixed valence of +3 and +4 and vacancy of A-site ions exists. The valence state of Ti ions can be altered by high-pressure and high-temperature. IR measurement indicates that the frequency for vibration of Ti-O bond increases as x increase.
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Key words:
- high pressure and high temperature synthesis /
- XPS /
- EPR /
- IR /
- mixed valence
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