Structure Refinement of the Semiconducting Compound Cu₃TaS₄from X-Ray Powder Diffraction Data

Abstract

The ternary compound Cu 3 TaS 4 has been investigated by means of X-ray powder diffraction and its structure has been refined by the Rietveld method. This compound is isostructural with the sulvanite mineral Cu 3 VS 4 , and crystallizes in the cubic P43m space group (No. 215), Z = 1, with unit cell parameters a = 5.5145(1) Å and V = 167.70(1) Å 3 . The refinement of 14 instrumental and structural parameters converged to R p = 4.4%, R wp = 6.8%, R exp = 5.5% and S = 1.2 for 4501 step intensities and 33 independent reflections.

Sulvanite Compounds Cu₃TMS₄ (TM = V, Nb and Ta): Elastic, Electronic, Optical and Thermal Properties using First-principles Method

“…These conditions also lead to a restriction on the value of the bulk modulus B as C 12 < B < C 11 , again satisfied by the present data. The table further shows that our optimized structural data are in good agreement with the available results obtained by other workers [5,[7][8][17][18].…”

“…The ternary compounds Cu 3 TMS 4 (TM =V, Nb, Ta) have been reported to be interesting materials which exhibit promising opto-electronic properties with relatively large optical band gap, p-type conductivity, photoemission in the visible range [1][2]. Despite the prospect only a few experimental and theoretical works have been reported in the literature [3][4][5][6][7][8]. Thermodynamic and experimental investigation on the mixed conductivity in Cu 3 VS 4 [3], infrared-reflectivity and Raman study of the vibronic properties of Cu 3 TMS 4 (TM = V, Nb, Ta) [4], experimental analysis of the optical and transport properties of Cu 3 TaS 4 thin film [1][2] have been reported.…”

Pressure-Induced Enhanced Optical Absorption in Sulvanite Compound Cu3TaX4 (X = S, Se, and Te): An ab Initio Study

“…Recent theoretical and experimental works 2−4 on sulvanite compounds report them to be indirect band gap semiconductors, exhibiting tunable photoemission properties, large optical band gaps, and excellent electro-optic properties. 5,6 The nontoxic, as well as earth-abundant elemental constituents, have attracted further attention of researchers in investigating the potential application of these compounds. They have cubic symmetry, and interestingly their band gap increases in substitutional sequence V → Nb → Ta but decreases in the sequence S → Se → Te.…”

The electronic and optical properties of the sulvanite compounds: a many-body perturbation and time-dependent density functional theory study

“…Also, sulvanite showed ionic con ductivity that is due to a small number of interstitial Cu + ions [15,16]. Different experimental techniques such as chemical reactions [17], pulse laser deposition [12][13][14] and melting/ annealing processes [18,19] have been implemented to grow sulvanite crystals. It is important to keep in mind that stoichi ometry sulvanite crystals with the ideal proportion 3:1:4 have never been grown, indicating that crystal impurities associated mainly with interstitial Cu ions and other atomic elements, and Cu and X vacancies are present as well [12][13][14][15][16][17][18][19].…”