Structure types and phase transformations in KMnCl3 and TlMnCl3

High-temperature structural evolution of caesium and rubidium triiodoplumbates

“…An attempt to detect the hightemperature polymorphic modification for rubidium triiodoplumbate has already been made [5] but it was not successful as well. An analysis of available literature data on high-temperature investigations of compounds which are isostructural to CsPbI 3 (TlMnI 3 and TlFeI 3 [10], InCdBr 3 [11], InFeBr 3 and InMnBr 3 [12], KMnCl 3 and TlMnCl 3 [13], KMnBr 3 [14]) has shown the existence of phase transformations in The averaged Pb-I distance in PbI 6 -octahedra increases from 3.244 Å at 298 K up to 3.266 Å at 593 K for orthorhombic CsPbI 3 , from 3.144 Å at 609 K up to 3.150 Å at 687 K for cubic CsPbI 3 and from 3.231 Å at 298 K up to 3.247 Å at 634 K for orthorhombic RbPbI 3 . The values for the averaged Pb-I distance are almost the same in both orthorhombic phases and appear to be shorter than the Pb-I distance (3.39 Å ) calculated from the sum of the Shannon ionic radii.…”

Thermodynamic evaluation and optimization of the (NaCl+KCl+MgCl2+CaCl2+MnCl2+FeCl2+CoCl2+NiCl2) system

“…The existence of different allotropes for KMnCl 3 is reported in the literature. According to Horowitz et al [43], the stable room temperature form, with the NH 4 CdCl 3 structure, is formed very slowly. A transition to a second form of KMnCl 3 occurs at a temperature which can vary between 150°C and 270°C [43], probably due to kinetic effects.…”

“…According to Horowitz et al [43], the stable room temperature form, with the NH 4 CdCl 3 structure, is formed very slowly. A transition to a second form of KMnCl 3 occurs at a temperature which can vary between 150°C and 270°C [43], probably due to kinetic effects. This new form is tetragonal with the GdFeO 3 structure [42].…”

Octahedral Tilting in Perovskites. I. Geometrical Considerations

“…Oxides and fluorides comprise the vast majority of perovskite compounds (Goodenough & Longo, 1970), but the perovskite structure is found for many combinations of cations and anions. Chlorides (Brynestad, Yakel & Smith, 1966;Horowitz, Amit, Makovsky, Ben Dor & Kalman, 1982), bromides (Knochenmuss, Reber, Rajasekharan & GEidel, 1986), hydrides (Messer, Eastman, Mers & Maeland, 1964), oxynitrides (Bacher et al, 1988) and sulfides (Clearfield, 1963;Rodier & Laruelle, 1970;No~l, Padiou & Prigent, 1975) are all known with the perovskite structure. Since the perovskite structure can accommodate such a wide variety of ions, the physical properties of perovskite compounds are wonderfully diverse.…”