X‐ray powder diffraction study of the Cu₂Cd_1–xMn_xSnSe₄ alloys

Abstract

The alloys of the Cu 2 CdSnSe 4 -Cu 2 MnSnSe 4 system were investigated using the X-ray powder method that showed the continuous solubility of the original system components at 670 K. The refinement of the crystal structures of Cu 2 MnSnSe 4 (space group (SG) I4 2m, a = 0.57362(4) nm, c = 1.14007(7) nm, c/a = 1.9875, R I = 0.0531, R P = 0.1186) and of the solid solution of Cu 2 Cd 0.5 Mn 0.5 SnSe 4 composition (SG I4 2m, a = 0.57935(2) nm, c = 1.14036(5) nm, c/a = 1.9683, R I = 0.0455, R P = 0.0902) was performed. It was established that Cd mixes statistically with Mn in its crystallographic position.The crystal structure of the Cu 2 MnSnSe 4 compound and of the solid solution of Cu 2 Cd 0.5 Mn 0.5 SnSe 4 composition are studied in detail in this paper. These isostructural phases are described in the stannite structural type (SG I42m (no. 121)) with the lattice parameters a = 0.57362(4) nm, c = 1.14007(7) nm and a = 0.57935(2) nm, c = 1.14036(5) nm, respectively. Atomic parameters were calculated in the isotropic approximation (R I = 0.0531 and R I = 0.0455 for Cu 2 MnSnSe 4 and Cu 2 Cd 0.5 Mn 0.5 SnSe 4 , respectively). The initial quaternary compounds form a continuous solid-solution series.

Lattice parameter values and phase transitions for the Cu2Cd1−zMnzSnSe4 and Cu2Cd1−zFezSnSe4 alloys

“…In recent works, lattice parameter values and phase diagrams for the Cu 2 Cd 1−z Mn z GeSe 4 , Cu 2 Cd 1−z Fe z GeSe 4 and Cu 2 Zn 1−z Fe z GeSe 4 alloy systems have been studied [6,7]. The X-ray powder diffraction study of the Cu 2 Cd 1−z Mn z SnSe 4 alloys has been given by Sachanyuk et al [8], but information on the phase diagram for this system has not as yet been reported.…”

“…1. The crystal structure of these compounds has been given in earlier works [4,5,[8][9][10][11][12], and it has been found that all of them have the stannite tetragonal structure (I42m), with unit cell parameter values a = 5.8337(2) Å, c = 11.4039(4) Å for the Cu 2 CdSnSe 4 [10], a = 5.694(2) Å, c = 11.286(4) Å for the Cu 2 FeSnSe 4 compound [12] and a = 5.7362(4) Å, c = 11.4007(7) Å for the Cu 2 MnSnSe 4 [8]. Matsushita et al [13] reported that Cu 2 CdSnSe 4 has a congruent type of melting at 1053 K (780 • C), while according to Olekseyuk and Piskach [10,14] it is formed incongruently at 1055 K (782 • C).…”

Magnetic properties of Cu2Cd1−zMnzGeSe4 and Cu2Cd1−zFezGeSe4 alloys

“…The X-ray powder diffraction study of the Cu 2 Cd 1−z Mn z SnSe 4 system has been reported in Ref. [12].…”

Magnetically induced ferroelectricity inCu2MnSnS4andCu2

“…Internal atomic coordinates are optimized starting from experimental data of Cu 2 MnSnS 4 [10] and Cu 2 MnSnSe 4 . [16] The 2×4×1 Monkhost-Pack k-point grid in the Brillouin zone is used. [17] Cu-3d4s, Mn-3d4s, Sn-5s5p, S-3s3p, and Se-4s4p electrons are treated as valence states.…”

“…Lattice constants are fixed to the experimental data: a = b = 5.514Å, c = 10.789Å for Cu 2 MnSnS 4 [10] and a = b = 5.736Å, c = 11.401Å for Cu 2 MnSnSe 4 [16] in the tetragonal I42m structure. In order to impose the experimentally observed AFM spin configuration in Cu 2 MnSnS 4 [10] with the propagation vector k = ( (c)) (note that, to our knowledge, the experimental magnetic configuration for Cu 2 MnSnSe 4 has not been reported yet).…”