Ferromagnetic order in single-crystalline (CdxAl y)[Cr2]Sez semiconductors

Measurements of the magnetic properties, the electrical conductivity and the Seebeck effect were performed on single crystals (CdxAly)[Cr2]Sez between 77 and 300 K. All samples have a ferromagnetic order with the Curie temperature of 130 K and the paramagnetic Curie–Weiss temperature of 155 K. Both these temperatures do not depend significantly on the Al substitution. The electrical conductivity of single crystals CdCr2Se4 doped with Al. was p-type and showed the change of log ¾ versus 1=T slope above 150 K. This fact is interpreted as being due to the onset of impurity conduction and structural defects