On the study of the solid–solid phase transformation of TlBiTe2.

The narrow gap semiconductor TlBiTe₂ undergoes a solid–solid phase transformation from the rhombohedral (D_3d) to the cubic (O_h) phase. The present paper deals with the study of this phase transformation combining the results of Differential Scanning Calorimetry (DSC) and Transmission Electron Microscopy (TEM). It has been found that during heating the transformation is an athermal activated process, which can be described only by a combination of more than one processes while during cooling it exhibits an expectable thermal hysteresis due to the volume difference. The results of the kinetic analysis combined with the electron microscopy findings, supported also by the Fourier Transform Infrared (FTIR) spectroscopy ones, lead to the conclusion that TlBiTe₂ undergoes a multiple-step, displacive, martensitic type transformation. [ABSTRACT FROM AUTHOR]