Structural phase transitions in elpasolites Rb₂NaDyF₆and Rb₂KDyF₆

The crystal structure and temperature dependence of the elpasolite Tl2LiYCl6

“…Single crystals may crack during post-growth cooling, due to phase transitions, anisotropic thermal expansion or lattice strain from the introduction of dopants (Doty et al, 2007;Onken et al, 2018). For elpasolites in particular, structural transitions involving the tilting or distortion of the LiX 6 and MX 6 octahedra have been observed (Flerov et al, 1998), and some of these transitions have been associated with twinning ISSN 1600-5767 (Bezbtosikov et al, 1983). While the crystal structure and phase transitions have been studied extensively in a number of Li-containing halide elpasolite systems (Doty et al, 2012;Flerov et al, 1998;Meyer & Dietzel, 1979), the work on A = Tl + elpasolites such as TLYC is relatively sparse.…”

Die Kristallstruktur von [(CH3)4N]2TeCl6 und über die Einschlußverbindung [(CH3)4N]2(CH3CN)TeCl6 / The Crystal Structure of [(CH3)4N]2TeCl6 and the Inclusion Compound [(CH3)4N]2(CH3CN)TeCl6

“…bei K2TeB r6 [22,23,24], m it einander verknüpft. Somit ist eine H ochtem peraturphase mit der Raum gruppe P4/mnc auch für ein Fluorid beobachtbar, das wie die Verbindung Rb2KDyF6 [25] bei R aum tem peratur in P 2 xln kristal lisiert. Lediglich bei V erbindungen in der R aum gruppe F d3c, welche bisher ausschließlich mit den voluminösen (CH 3)4N +-Kationen für die Position der A-Teilchen beobachtet wurden, ist noch kein V ertre ter mit X = F bekannt.…”

Temperature phase transitions in Rb2KRe3+F6 elpasolites - Raman spectroscopy study

“…The changes of external parameters cause structural phase transitions in these crystals. The temperature phase transitions have been investigated earlier in [7][8][9][10][11][12][13][14][15][16] and phase transitions under hydrostatic pressure as well as P-T phase diagrams in [17,18]; detailed symmetry analysis was proposed in [19]. It should be pointed out that these successions of phase transitions differ considerably from those observed in oxide analogues, that attracts special interest to them.…”