PREPARATION AND CHARACTERIZATION OF CU2ZNGES4-YSEY

Cu2ZnGeS4 can be prepared in both tetragonal stannite and orthorhombic wurtz-stannite phases, whereas Cu2ZnGeSe4 exists only in the tetragonal phase. Selenium can be substituted for sulfur up to 100% in the tetragonal structure of Cu2ZnGeS4–ySey prepared at 700 °C and up to 75% in the orthorhombic structure prepared at 900 °C. The temperature at which the phase transformation takes place was found to increase with higher selenium concentration. Iron was substituted into both forms of Cu2Zn1–xFexGeS4–ySey, and the resulting magnetic properties indicated that the Fe-Fe superexchange interactions are the same in both structures. © 1990, American Chemical Society. All rights reserved.