Phase formation and physical properties of Mn_xCd_1-xIn₂Te₄ ingots grown by the Bridgman method

Diluted magnetic semiconductor Mn_xCd_1-xIn₂Te₄ (x=0.1, 0.22 and 0.4) ingots were grown by the Bridgman method. The structure and composition of different phases and the compositional distribution along the axis and radius of the ingots were analyzed. α+β+β₁ structures are formed at the tip of the ingots. α and β phases are crystallized from the melt while β₁ phase is precipitated from α phase when temperature is below solidus. The content of β phase increases with the growth process, and finally, a pure β phase-region is formed. At the end of the ingots, an In₂Te₃-type phase with a fcc structure is crystallized. There are two distinct interfaces between the different adjacent phase-regions. The band gap of Mn_xCd_1-xIn₂Te₄ shifts towards the high energy side with the increase of x. At higher temperatures(50-300 K) the variation of magnetic susceptibility with temperature in Mn_xCd_1-xIn₂Te₄ follows the Curie-Weiss (C-W) law. A paramagnetic behavior exists at lower temperature (<50 K). The antiferrornagnetic exchange of Mn²⁺ increases with the increase of x.