Growth by Vapor-Liquid Transport Method and Properties of Ferromagnetic Semiconductor CdCr₂S₄ Single Crystals

Abstract

Single crystals of ferromagnetic semiconductor CdCr₂S₄ are grown by a vapor-liquid transport method, and their crystallographic and magnetic properties are characterized. The magnetic properties scatter rather widely, which is discussed in relation to the nonstoichiometry in the compound. The results are summarized as follows.
(1) Using CdS and CrCl₃ pellets in the mole ratio 2 : 1, CdCr₂S₄ single crystals are grown by the vapor-liquid transport for 4 days at the source and the growth zone temperatures 985 and 950°C, respectively. The single crystals obtained are octahedral and have a maximum side length of 4 mm. Larger octahedral CdCr₂S₄ single crystals having a side length of about 5 mm are grown by winding a platinum ribbon on the CrCl₃ pellet.
(2) Curie constant C and paramagnetic Curie temperature θ range from 3.40 to 4.50 emu · deg/mol and from 141 to 165 K, respectively. This scatter is attributed to the difference of nonstoichiometry in the compound.