High-pressure behaviour of synthetic weberite-type Mn2+2Sb5+2O7: An in situ single-crystal X-ray study

• Published in: Solid state sciences 2013-07, Vol.21, p.85-90
• Main Authors: Chelazzi, L., Boffa Ballaran, T., Lepore, G.O., Bindi, L., Bonazzi, P.
• Format: Article
• Language: English
• Subjects: Antimonates; Compressibility; Condensed matter: structure, mechanical and thermal properties; Deformation and plasticity (including yield, ductility, and superplasticity); Equations of state of specific substances; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; High pressure; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Physics; Single-crystal X-ray diffraction; Thermodynamic properties; Weberite
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2013.04.012

An in situ high-pressure X-ray diffraction study has been carried out at room temperature up to 9.26 GPa on synthetic Mn2Sb2O7 having a weberite-3T structure. A 2nd-order Birch–Murnaghan Equation of State (EoS) was used to refine the pressure–volume data. The refinement of the unit-cell volume and of the isothermal bulk modulus at room pressure leads to: V0 = 782.7(2), KT0 = 150(1) GPa. Unit-cell parameters decrease gradually as a function of pressure with a bulk modulus anisotropy scheme, with a being the softest direction. The overall mean polyhedral distances are quite constant, indicating a scarce compressibility of both the A and B polyhedra in the pressure range investigated. The compressional behaviour of Mn2Sb2O7 is compared with that shown by ingersonite, Ca3MnSb4O14, and synthetic orthorhombic Ca2Sb2O7. [Display omitted]