Effects of W6+ occupying Sc3+ on the structure,vibration,and thermal expansion properties of scandium tungstate

• 作者: Dongxia Chen Qiang Sun Zhanjun Yu Mingyu Li Juan Guo Mingju Chao Erjun Liang
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES
• 页码范围: 502-509
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-1056/abd7d4

摘要

We experimentally investigate effects of W6+ occupying the sites of Sc3+ in the unit cell of Sc2W3O12 (Sc8W12O48)on the structure,vibration and thermal expansion.The composition and structure of the doped sample (Sc6W2)W12O48±δ(with two W6+ occupying two sites of Sc3+ in the unit cell of Sc8W12O48) are analyzed and identified by combining the x-ray photoelectron spectroscopy and the synchronous x-ray diffraction with first-principles calculations based on density functional theory.Results show that the crystal with even W6+ occupying even Sc3+ in the unit cell is stable and maintains the orthorhombic structure at room temperature.The structure of the doped sample is similar to that of Sc2W3O12,and with even W occupying even positions of Sc in the unit cell and constituting the WO6 octahedra.Raman analyses show that the doped sample possesses stronger W-O bonds and wider Raman linewidths than those of Sc2W3O12.The sample doped with W also exhibits intrinsic negative thermal expansion in the measured range of 150 K-650 K.