High temperature structure and vibrational properties of GdVO4

• Published in: Materials chemistry and physics 2023-02, Vol.295, p.127120, Article 127120
• Main Authors: Anitha, M., Rao, K. Sandeep, Syed, Rajak, Kesari, S., Rao, R., Singh, D.K., Achary, S.N., Kain, Vivekanand
• Format: Article
• Language: English
• Subjects: Crystal chemistry; Raman spectroscopy; Thermal expansion; Vanadates; Vibrational properties; X-ray diffraction; Zircon
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2022.127120

In this manuscript the temperature evolution of crystal structure and vibrational properties of tetragonal GdVO4 as observed from in situ high temperature powder XRD and Raman spectroscopic studies are reported. The material shows anisotropic expansion with a larger coefficient of thermal expansion along c-axis (αc) compared to that along the a-axis (αa). The average axial thermal expansion coefficients in the temperature range of 298–1373 K are: αa = 3.75 × 10−6 K−1 and αc = 11.1 × 10−6 K−1. The degree of anisotropy in thermal expansion decreases with increasing temperature. The thermal expansion behavior of GdVO4 was mainly contributed by the orientation and expansion of Gd–O bonds in the structure. The temperature dependent Raman spectroscopic investigations indicate decreasing trend of all the observed phonon mode frequencies. All the low energy modes show larger anharmonicity compared to the high energy stretching modes and they contribute significantly to the expansion of GdVO4. [Display omitted] •Structural and vibrational properties of GdVO4 at high temperature have been studied.•Coefficients of axial thermal expansions of GdVO4 increase systematically with increase in temperature.•Anisotropy in lattice expansion has been related to structural parameters at higher temperature.•Low frequency Raman modes show larger anharmonicity and they contribute more to lattice expansion.