0000000000846556
AUTHOR
B. Kosturek
Optical investigation of phase transitions in Di(Tetraethylammonium) pentachloroantimonate(III) [N(C2H5)4]2SbCl5
Abstract Spontaneous changes of linear birefringence in the [N(C2H5)4]2SbCl5 crystal were measured in the temperature range 200–500 K. Presence of two phase transitions at 219 K (monoclinic to orthorhombic) and at 347 K (orthorhombic to tetragonal) was confirmed. Two new phase transitions were found: -at 438 K (tetragonal to tetragonal) and at 467 K -to cubic phase.
Structure and phase transitions in the ferroelastic [C(NH2)3]3Bi2Br9crystal
Differential scanning calorimetry, dilatometric, dielectric and linear birefringence measurements have been used to study the ferroelastic [C(NH2)3]3Bi2Br9 crystal. The x-ray studies showed that it crystallizes at room temperature in the monoclinic symmetry, space group P21/m. The crystal undergoes a complex sequence of phase transitions: at 311 K, 333.5 K, 350 K, 415 K and 425 K. All phase transitions were found to be of first order type. The ferroelastic domain structure is maintained from room temperature up to 425 K. The temperature measurements of the linear birefringence and optical observations suggest the tetragonal symmetry of the parent paraelastic phase above 425 K.
Crystal structure, phase transitions and ferroelastic properties of [(CH3)2NH2]3[Bi2Cl9]
Abstract A sequence of structural phase transitions in [(CH3)2NH2]3[Bi2Cl9] (DMACB) is established on the basis of differential scanning calorimetry (DSC) and dilatometric studies. Four phase transitions are found: at 367/369, 340/341, 323/325 and 285/292 K (on cooling/heating). The crystal structure of DMACB is determined at 350 K. It crystallizes in monoclinic space group P21/n: a=8.062(2), b=21.810(4), c=14.072(3) A, β=92.63(3)°, Z=4, R1=0.0575, wR2=0.1486. The crystal is built of the double chain anions (“pleated ribbon structure”) and the dimethylammonium cations. Dielectric studies in the frequency range 75 kHz–900 MHz indicate relatively fast reorientation of the dimethylammonium cat…
CCDC 189320: Experimental Crystal Structure Determination
Related Article: M.Wojtas, G.Bator, R.Jakubas, J.Zaleski, B.Kosturek, J.Baran|2003|J.Solid State Chem.|173|425|doi:10.1016/S0022-4596(03)00137-3
CCDC 607733: Experimental Crystal Structure Determination
Related Article: R.Jakubas, J.Zaleski, B.Kosturek, G.Bator|1999|J.Phys.:Condens.Matter|11|4731|doi:10.1088/0953-8984/11/24/314