Crystal Chemistry of CdIn₂S₄, MgIn₂S₄, and MnIn₂S₄ Thiospinels under High Pressure

Abstract

We report X-ray diffraction measurements in CdIn2S4, MgIn2S4, and MnIn2S4 thiospinels at room temperature and high pressures. The pressure dependences of the structural parameters have been determined and compared to those from theoretical calculations. It is found that the three thiospinels have similar bulk moduli (B 0) between 75 and 80 GPa (B 0′ ∼ 3). The degree of inversion of these thiospinels has also been determined. The three thiospinels undergo a phase transition toward a defect LiTiO2-type structure above 9.5, 8.3, and 6.8 GPa in CdIn2S4, MgIn2S4, and MnIn2S4, respectively. Interestingly, the low- and high-pressure phases belong to the same symmetry group (Fd-3m), the transition mechanism being associated to the migration of the tetrahedrally coordinated cations to a Wyckoff position of higher multiplicity, where these cations present an octahedral environment. The new postspinel phase exhibits a larger compressibility than the spinel phase for the three compounds, likely due to the presence of stoichiometric vacancies in the unit cell as it occurs for defect chalcopyrites and stannites. The relation between the bulk and the polyhedral compressibilities is discussed as well.

First-principles calculations of the electronic, optical and elastic properties of CdIn2S4thiospinel at ambient and elevated pressure

“…In particular, the C ij values reported here can be compared only to other theoretical estimations and only one experimental study(Table II). The calculated values of bulk modulus at zero pressure (especially calculated by LDA) are in good agreement with the experimental result from Ref [13]…”

“…shows how the unit cell volume of CdIn 2 S 4 varies with pressure in comparison with the experimental data from Ref [13]…”

“…Their crystal structure is characterized by a partial degree of cation inversion, which leads to a high concentration of antisite defects. The concentration of these defects can be adjusted by varying external pressure, which makes thiospinels be materials of choice for defect engineering applications [ 13 ]. Furthermore, indium thiospinels have been recently proposed as ideal materials for photovoltaic cells operating with an intermediate band.…”

X-ray diffraction study on pressure-induced phase transformations and the equation of state of ZnGa2Te4

“…Among other techniques, they have been studied by XRD, being several pressure-induced transitions reported. [6][7][8][9][10][11][12][13][14][15] The reversibility of these transitions is subject of dispute. In some cases, it has been found that the transitions are not reversible, being metastable polymorphs recovered at ambient conditions after decompression.…”

Joegoldsteinite: A new sulfide mineral (MnCr2S4) from the Social Circle IVA iron meteorite

“…Nevertheless, chalcospinels, thiospinels, and selenospinels have been used for geophysical studies because their phase transitions are good analogs for those of oxyspinel compounds. These are known to show phase transitions in high-pressure regimes (e.g., 29 GPa for FeCr 2 O 4 , Shu et al 2007), while thiospinel transitions occur at lower pressure (e.g., 9 GPa for FeCr 2 S 4 , Amiel et al 2011;and Manjon et al 2014;Santamaría-Pérez et al 2012).…”