The magnetization in (Zn1-xCox)Ga2O4 (x=0.05, 0.10, and 0.20) diluted magnetic semiconductors depending on Co atoms in tetrahedral and octahedral sites

Abstract

The present study describes magnetic interactions in (Zn1-xCox)Ga2O4 (x = 0.05, 0.10, and 0.20) particles dependant on Co atoms in both tetrahedral and octahedral sites. The effects of substituted Co atoms to magnetic character are analyzed using Curie-Weiss law. The ferromagnetic character is found dominant in (Zn1-xCox)Ga2O4 semiconductors for x values lower than 0.10; in addition, a specific hysteresis with 139 +/- 50 Oe coercivity is observed for 5% Co-doped ZnGa2O4. The high Co amount in tetrahedral site increased the number of antiferromagnetic couplings and the hysteresis at 300 K disappeared for (Zn0.80Co0.20)Ga2O4 particles. Furthermore, the Co+3 ions in the octahedral site decreased mu(eff) values, per Co amounts, in the range of 4.89 +/- 0.01 mu(B)/Co to 4.44 +/- 0.02 mu(B)/Co, because of enhancing paramagnetic behaviors.