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Tetragonal aluminium sulfide crystallizing with the spinel defect structure of the β-In2S3 type has been prepared at ambient pressure. IR and Raman spectra of this compound and of α-Al2S3 are reported and discussed in relation to their crystal structures

The system CdIn 2 S 4− x Se x is investigated by means of X-ray diffraction. There are three phases present in the system: (i) a cubic spinel phase for x = 0 to x = 1.25, (ii) a rhombohedral phase of ZnIn 2 S 4 type for x = 1.75 to x = 2.75, and (iii) a tetragonal thiogallate phase for x = 3.5 to x = 4.0.

In the course of attempts to synthesize new compounds of the composition Ag2HgMX4 four hitherto not reported compounds (I)-(IV) are obtained by solid state reaction at 700 °C, starting from Ag, Ge(Sn), S(Se), and HgS or HgSe.

Three new compounds, Ag2HgGeS4, Ag2HgSnS4, and Ag2HgSnSe4, crystallizing in the wurtzstannite type structure have been prepared by solid state reactions at 700°C and characterized by X-ray powder methods. A fourth compound of similar composition Ag2HgGeSe4, with an hitherto unknown structure crystallizes cubically with a = 10.796 A.

Single crystals of LaOCl have been grown from molten LaCl3 by a slow cooling technique. The Raman spectra of these crystals have been recorded and the frequencies and symmetries of the different lines determined by means of polarized Raman scattering.

The crystal structure of Ga 1.78 Cr 0.89 S 4 has been determined from single crystal X-ray diffraction data and refined to R = 0.026. It crystallizes trigonally in a defect variant of the FeGa 2 S 4 -type with the space group P3 m 1 with z = 1 and lattice constants a = 360.43(2) and c = 1194.86 (2) pm with Ga atoms occupying the tetrahedral sites and Cr atoms the octahedral sites. The electrical conductivity of Ga 1.78 Cr 0.89 S 4 measured on powder samples is about 7.10 −5 ohm −1 cm −1 at 400°C with an activation energy for conduction of 1.2eV.

The following sulphides were precipitated with hydrogen sulphide from solutions of naphthenates in organic solvents: In2S3, CoS, NiS, CuS, ZnS, CdS, HgS, PbS, Ag2S and the thiospinels NiIn2S4, CdIn2S4 and HgIn2S4. Not precipitated are chromium (II) and chromium (III). The ir-spectra of the naphthenates are discussed.