Crystal structure of the ternary semiconductor Cu₂In_14/3□_4/3Se₈determined by X-ray powder diffraction data

Abstract

The crystal structure of the partially ordered vacancy compound Cu2In14/3□4/3Se8, belonging to the system I3-III7-□2-VI12, was analyzed using X-ray powder diffraction data. Several structural models were derived from the structure of the selenium-rich phase β-Cu0.39In1.2Se2 by permuting the cations in the available Wyckoff positions. The refinement of the best model by the Rietveld method in the tetragonal space group P$\overline 4 $ 2c (No 112), with unit-cell parameters a = 5.7487(3) Å, c = 11.5106(6) Å, V = 380.40(3) Å3, led to Rp = 9.0%, Rwp = 9.9%, Rexp = 7.2%, S = 1.4 for 134 independent reflections. This model has the following Wyckoff site atomic distribution: Cu in 2e (0,0,0); In in 2b (½,0,¼), 2d (0,½,¼), and 2f (½,½,0);□ in 2f (½,½,0); Se in 8n (x,y,z).

On the crystal structure of the ordered vacancy compound Cu3In5Te9

“…This behavior was also observed in CuFeInSe 3 [25], with composition I-II-III-VI 3 , and in the OVC's Cu 3 In 7 Se 12 [26] and Cu 3 In 7 Te 12 [27,28] [27,28], AgIn 5 Te 8 [32] and AgInTe 2 [33].…”

Evidence of a new ordered vacancy crystal structure in the compound Cu3In7Te12

“…The Rietveld refinement [19] of the whole diffraction pattern was carried out using the Fullprof program [20,21], with the unit cell parameters found in the indexing. For the refinement of Cu 3 In 7 Te 12 , the atomic coordinates of the compound Cu 3 In 7 Se 12 [17], were used as initial model, with the cation distribution shown in Table III. The angular dependence of the peak full width at half maximum (FWHM), was described by the Cagliotti's formula [22].…”

“…A revision of the diffraction lines, taking into account the sample composition, unit cell parameters, and lattice-type, suggests that this material is isostructural with Cu 3 In 7 Se 12 . This is the first compound with the I 3 -III 7 -[] 2 -VI 12 formula which has been reported to crystallize in a tetragonal structure with space group P 4 2c (Nº 112) [17]. The resulting X-ray powder diffraction data for Cu 3 In 7 Te 12 will be submitted to the Powder Diffraction File of the International Centre for Diffraction Data (ICDD) [18].…”

Crystal structure, electrical, and optical properties of Cu3In7Te12 ordered defect semiconducting compound

“…Powder X‐ray diffraction analysis was made to determine the crystal structure and the unit cell parameters of Cu 3 In 7 Te 12 . For the Rietveld refinement of the diffraction patterns, the atomic coordinates of the isostructural compound Cu 3 In 7 Se 12 were used as initial model in the analysis. Figure shows the calculated and difference profiles for the final cycle of the refinement.…”