0000000001304538
AUTHOR
M. Wojtas
showing 8 related works from this author
Crystal structure, phase transition and ferroelectric properties of the [(CH3)3NH]3[Sb2Cl9(1 x)Br9x] (TMACBA) mixed crystals
2003
The paraelectric–ferroelectric phase transition in the [(CH3)3NH]3[Sb2Cl9(1−x) Br9x] (TMACBA) mixed crystals is investigated by the differential scanning calorimetry, dilatometric and dielectric methods. The phase transition is found at 363.5, 362.7, 360.5 and 350.9 K (on cooling) for TMACBA crystals with x = 0, 0.02, 0.17 and 0.42, respectively. The crystal structures of the pure bromine analogue (x = 1), TMABA, and the mixed crystal TMACBA (x = 0.55) are determined at 297 K. TMABA crystallizes in the trigonal space group Rc: a = 15.098(2) A, c = 21.906(4) A, Z = 3, R1 = 0.0393, wR2 = 0.0746. Its structure is built up of discrete Sb2Br93− bioctahedra and disordered trimethylammonium cation…
Crystal structure and dielectric properties of the [(CH3)2NH2]3Sb2(1-x)Bi2xCl9(DMACAB) mixed crystals
2001
Phase transitions in [(CH3)2NH2]3Sb2(1-x)Bi2xCl9 (DMACAB) mixed salts in the composition range 0≤x≤0.41 have been investigated by the pyroelectric method and dielectric measurements over the frequency range from 75 kHz to 900 MHz. The phase situation is additionally confirmed by the differential scanning calorimetry (DSC) and dilatometric techniques. A transition from the paraelectric (PE) to the ferroelectric (FE) phase is observed for crystals with 0≤x≤0.14. Pyroelectric measurements support the presence of polar phases. The dynamic dielectric behaviour of ferroelectric systems is found to be determined by the existence of two independent relaxators. The low-frequency relaxator reveals a …
Structure and properties of 2-cyanopyridinium perchlorate [2-CNPyH][ClO4]
2006
The crystal structure of 2-cyanopyridinium perchlorate, [2-CNPyH][ClO4], has been determined at 100 (phase II) and 293 K (phase I). It is monoclinic P 21 at 100 K and orthorhombic P 212121 at 293 K. The dynamic properties of the crystal were studied by differential scanning calorimetry, dilatometry, pyroelectric, dielectric, proton (1H NMR), chlorine (35Cl NMR) magnetic resonance spectroscopies and the infrared method. The crystal undergoes a structural phase transition () at 170 K characterized by a complex mechanism involving both 'order–disorder' and 'displacive' contributions. It reveals pyroelectric properties below 170 K. The dielectric relaxation existing over phase I is due to the m…
CCDC 189320: Experimental Crystal Structure Determination
2004
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 270367: Experimental Crystal Structure Determination
2006
Related Article: O.Czupinski, M.Wojtas, J.Zaleski, R.Jakubas, W.Medycki|2006|J.Phys.:Condens.Matter|18|3307|doi:10.1088/0953-8984/18/12/012
CCDC 208515: Experimental Crystal Structure Determination
2006
Related Article: M.Wojtas, G.Bator, R.Jakubas, J.Zaleski|2003|J.Phys.:Condens.Matter|15|5765|doi:10.1088/0953-8984/15/33/310
CCDC 208514: Experimental Crystal Structure Determination
2006
Related Article: M.Wojtas, G.Bator, R.Jakubas, J.Zaleski|2003|J.Phys.:Condens.Matter|15|5765|doi:10.1088/0953-8984/15/33/310
CCDC 270368: Experimental Crystal Structure Determination
2006
Related Article: O.Czupinski, M.Wojtas, J.Zaleski, R.Jakubas, W.Medycki|2006|J.Phys.:Condens.Matter|18|3307|doi:10.1088/0953-8984/18/12/012