Structure du sulfure de gallium et de potassium, KGaS2

Rubidium thiogallate

“…1. Bond lengths and angles compare well with those reported in the literature (Devi & Vidyasagar, 2002;Schmitz & Bronger, 1975;Lemoine et al, 1984;Yao & Ibers, 2004).…”

Influence of Alkali Metal Substitution on the Phase Transition Behavior of CsGaQ2 (Q = S, Se)

“…This observation can easily be interpreted by DFT simulations performed by Feng et al for KGaSe 2 [8] and by us for the cesium compounds [6,7,13] and RbGaSe 2 [11]. While these calculated values are in good agreement with experimental data for the sulfides, significant deviations (>1 eV) between the experimental and calculated band gaps were obtained for all selenides [7][8][9][10][11]. These calculations further revealed direct band gaps for the pure ternary chalcogenides.…”

“…The low-temperature polymorph CsGaQ 2 -mC64 [6,7], as well as KGaQ 2 [8,9] and RbGaQ 2 (Q = S, Se) [10,11], crystallize in the TlGaSe 2 structure type ( Figure 1, Table 1 610 °C), we decided to explore the possibilities of the formation of solid solutions of these compounds with RbGaQ2 and KGaQ2. As the compounds KGaQ2 [8,9], RbGaQ2 [10,11] and the low-temperature phases CsGaQ2-mC64 [6,7] (Q = S, Se) all crystallize isotypically in the TlGaSe2 structure type, the formation of solid solutions Cs1−xMxGaQ2-mC64 (M = K, Rb; Q = S, Se; x = 0-1) should be possible. CsGaTe2 [12] also crystallizes in the TlGaSe2 structure type, but no phase transition occurs upon heating of this compound.…”

“…The low-temperature polymorph CsGaQ2-mC64 [6,7], as well as KGaQ2 [8,9] and RbGaQ2 (Q = S, Se) [10,11], crystallize in the TlGaSe2 structure type ( Figure 1, Table 1 showing: (a) the stacking of the anionic layers in the TlGaSe 2 structure type; (b) the supertetrahedral building blocks Ga 4 Q 10 of these layers; (c) coordination polyhedra of the alkali metal sites; (d) the arrangement of the anionic chains in the KFeS 2 structure type; (e) the SiS 2 analogous anionic chain; and (f) the coordination of the cesium site. The high-temperature polymorphs CsGaQ 2 -mC16 (Q = S, Se) crystallize in the KFeS 2 structure type ( Figure 1).…”

“…Tables S1 and S2 list all the observed Raman shifts in all of the solid solution series, as well as an assignment of the vibrational modes. The slight blue shift of all vibrations in the spectra of the lighter alkali metals indicate slightly stronger bonds Ga-Q, corresponding to the smaller distances d(Ga-Q) in the rubidium and potassium compounds [6][7][8][9][10][11]. In the solid solutions of Cs1−xRbxGaS2-mC64 (x = …”