Preparation and investigation (Cu–III–Se₂)_1–x(NbSe)_x alloys (III: Ga, In) with x = 1/2

Abstract

Polycrystalline samples of quaternary (Cu–III–Se2)1–x (NbSe)x alloys (III: Ga, In) with x = 1/2 (nominally CuNbGaSe3 and CuNbInSe3) were prepared by the usual melt and anneal technique. The analysis showed a large solubility of Nb in the ternary structures. The unit cell parameters of CuNbGaSe3 (a = 5.617 ± 0.001 Å; c = 11.024 ± 0.003 Å; c /a = 2.02; V = 348 ± 1 Å3) and CuNbInSe3 (a = 5.779 ± 0.001 Å; c = 11.620 ± 0.003 Å; c /a = 2.01; V = 388 ± 1 Å3) were very close to those of the respective ternaries, CuGaSe2 and CuInSe2. Nevertheless, indexation of the diffraction pattern of CuNbGaSe3 suggested, for this alloy, a space group transition from I$ \bar 4 $2d to P$ \bar 4 $2c analogous to CuFeInSe3, recently reported. From DTA measurements it was found that CuNbGaSe3 and CuNbInSe3 are ordered samples with order–disorder transition temperatures of ∼976 K and ∼910 K, and melted incongruently at ∼1185 K and ∼1046 K, respectively. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Synthesis and Crystal Structure of Three New Quaternary Compounds in the system Cu-Mn-III-Se3 (III = Al, Ga, In)

“…These materials crystallize with tetragonal symmetry in the space group I4 2d (N°122), and the addition of a Fe-Se binary compound produces alloys of the type (Cu-IIISe 2 ) 1-x (FeSe) x 2 . Some previous results on the formation, structural characterization, thermal and magnetic properties on these alloys with compositions Cu-Fe-III-Se 3 (x = ½), Cu-Fe 2 -III-Se 4 (x = ⅔) and Cu 2 -Fe-III-Se 5 (x = ⅓) have been reported [3][4][5][6][7][8][9][10][11][12][13][14][15] . All these phases fulfill the rules of formation of adamantane compounds 2 and belong to the normal semiconductor compound families of the third, fourth and fifth-order derivatives of the II-VI binary semiconductors, respectively 16 .…”

The new P-chalcopyrite compound Cu2FeIn2Se5; synthesis, thermal analysis (DTA), and crystal structure analysis by X-ray powder diffraction (XRPD)

“…Adamantane compounds are binary, ternary, or quaternary normal tetrahedral structure compounds that are closely related to either cubic or hexagonal diamond [5]. In our laboratories, we have been studying these type of alloys from its synthesis, thermal and magnetic properties as well as their crystal structures [6][7][8][9][10][11][12][13]. Due to the great variety of possible compositions, these materials can be useful for applications such as tunable semiconductors [14], photovoltaics [15], non-linear optics [16], thermoelectrics [17], and particularly as spintronic device [18] due to the discovery of room-temperature ferromagnetism and super-paramagnetism in some of these materials [19].…”