A位具有混合价态的钙钛矿氧化物Eu1-xKxTiO3（x=0.2，0.32）的高温高压合成

The Synthesis of Perovskites Eu1-xKxTiO3 (x=0.2, 0.32) with Mixed Valence in A-Site under High Pressure and Temperature

1.
Department of Physics, Jilin University, Changchun 130023, China;
2.
Key Laboratory of Inorganic Synthesis, Changchun 130023, China;
3.
International Center for Materials Physics, Academia Sinica, Shenyang 110015, China

摘要: 以TiO2和Eu2O3为原料，利用固相反应法在4.0 GPa和1 090 ℃下合成了钙钛矿氧化物Eu1-xKxTiO3（x=0.2，0.32）。XRD测量表明样品为立方结构。151Eu Mossbauer谱测试给出同质异能移位分别为～0 mm/s和～-13 mm/s的两个吸收峰，表明Eu离子为+2和+3混合价。在480和6 480 G的磁场范围内只观察到一个线宽为3 140 G、g因子为2.00的信号，这是由Eu2+产生的。在EPR谱上没有观察到Ti3+和A位缺位的信号，说明在样品中的Ti在B位是+4价的。在固态反应中，Eu3+离子比Ti4+离子更容易被还原。
- 高压高温 /
- Eu1-xKxTiO3 /
- Mossbauer谱 /
- EPR
Abstract: The perovskite oxides Eu1-xKxTiO3 (x=0.2 and 0.32) were synthesized under 4.0 GPa and at 1 090 ℃ with the starting materials TiO2 and Eu2O3. XRD measurements show that the samples are cubic. 151Eu Mossbauer spectra exhibits two peaks at ca. 0 and -13 mm/s, which suggests that Eu ions are in mixed valence of +2 and +3. Only one signal with linewidth 3 140 Guss and g=2.00 is observed within the range of 480 to 6 480 G. The absence of the signals associated with Ti3+ and A-site deficiency indicates that Ti ions is Ti4+. In the process of solid state reaction, Eu3+ ions are easier reduced than Ti4+.
- high pressure and high temperature /
- Eu1-xKxTiO3 /
- Mossbauer spectrum /
- EPR

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