(Cu0.4Al0.3)TaSe2: PREPARATION AND CRYSTAL STRUCTURE ANALYSIS FROM X-RAY POWDER DIFFRACTION
Abstract:
<div style="text-align: justify;">A new phase of the (CuAlSe<sub>2</sub>)<sub>1-x</sub>(TaSe)<sub>x</sub> alloy system was synthesized by the melt and annealing technique and studied by SEM, DTA, and XRPD techniques. Its structure has been refined by the Rietveld method using X-ray powder diffraction data. The new alloy corresponds with the stoichiometry Cu<sub>0.4</sub>Al<sub>0.3</sub>TaSe<sub>2</sub>. This compound crystallizes in the hexagonal space group 𝑃6ത𝑚2 (Nº 187) with a MoS<sub>2</sub>-type structure, and unit cell parameters a = 3.455(2) Å, c = 13.423(4) Å, V = 138.7(1) Å3, Z =2. The crystal structure is based on the MoS<sub>2</sub>- type of stacking of TaSe<sub>2</sub> layers with a partial ordering of Cu and Al cations over the tetrahedral sites. The powder pattern was composed of 63.1% of the principal phase Cu<sub>0.4</sub>Al<sub>0.3</sub>TaSe<sub>2</sub> and 29.9% of CuAlSe<sub>2</sub>, 7.0% of TaSe<sub>3</sub>, as the secondary phases. </div>
<div style="text-align: justify;">A new phase of the (CuAlSe<sub>2</sub>)<sub>1-x</sub>(TaSe)<sub>x</sub> alloy system was synthesized by the melt and annealing technique and studied by SEM, DTA, and XRPD techniques. Its structure has been refined by the Rietveld method using X-ray powder diffraction data. The new alloy corresponds with the stoichiometry Cu<sub>0.4</sub>Al<sub>0.3</sub>TaSe<sub>2</sub>. This compound crystallizes in the hexagonal space group 𝑃6ത𝑚2 (Nº 187) with a MoS<sub>2</sub>-type structure, and unit cell parameters a = 3.455(2) Å, c = 13.423(4) Å, V = 138.7(1) Å3, Z =2. The crystal structure is based on the MoS<sub>2</sub>- type of stacking of TaSe<sub>2</sub> layers with a partial ordering of Cu and Al cations over the tetrahedral sites. The powder pattern was composed of 63.1% of the principal phase Cu<sub>0.4</sub>Al<sub>0.3</sub>TaSe<sub>2</sub> and 29.9% of CuAlSe<sub>2</sub>, 7.0% of TaSe<sub>3</sub>, as the secondary phases. </div>
DOI: 10.48141/SBJCHEM.v28.n29.2020.01_DELGADO_pgs_01_06.pdf
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