Dislocations and Te precipitates of Cd0.9Mn0.1Te: V crystal grown by Tellurium solution vertical Bridgman method

Abstract

A successful growth of Cd0.9Mn0.1Te (CMT) ingot (vanadium doping concentration of 1 × 1017 atoms/cm3) was achieved by using the Tellurium (Te) solution vertical Bridgman method. Using diffraction in the transmission electron microscope (TEM), the cell parameter of grown crystal was reckoned at 0.6496 nm. The [1 1 2¯] zone-axis diffraction pattern (DP) was obtained and indexed as the (1 1 1), the (1 3¯ 1¯), the (2 2¯ 0) and the (3¯ 1 1¯), respectively. Bright field (BF) image of the [1 1 2¯] zone-axis showed bend contours which caused by the lattice planes physically rotate and the lattice defects. A screw dislocation was assigned according to the changes characteristic of the bend contour when crossing the 1 3¯ 1¯ bend contour. And by imaging technique of high-resolution TEM (HRTEM), an edge dislocation and a set of stacking faults were recognized in the interfaces between Te precipitates and CMT: V. Then through the selected area diffraction (SAD) method, an array of rod-shape monoclinic-phase Te precipitates was identified parallel to the [1 1¯ 0] direction, i.e. the slip direction of the dislocation. The [1 0 0] zone-axis diffraction spots of the Te precipitates were superimposed on the [1¯ 1 2] zone-axis of CMT: V. 020 spot of the Te precipitates was a double diffraction spot produced by interactions of the Te precipitates and CMT: V reflections. Moreover, the results indicated the moiré fringes were formed in the area of misfitted and rotational lattices of the Te precipitates and CMT: V. They were interference interactions which magnified the differences of lattice spacing and relative orientation.