Sodium Doping Could Enhance the Room Temperature Ferromagnetism of (ZnO): Mn Diluted Magnetic Semiconductors

摘要

Zn_(0.995-y)Mn_(0.005)Na_yO (y = 0.00 to 0.010) nano-crystal powders are synthesized by a sol-gel method. All samples have ferromagnetism at room temperature and are composed of wurtzite ZnO with hexagonal structure without any secondary phases. The ferromagnetism is enhanced while 0.005 < y < 0.007 (Na:Mn = 1:1 to 1.4:1). The sample of Zn_(0.988)Mn_(0.005)Na_(0.007)O has the largest coercivity of 62.018GS;;saturation magnetization of 1.751 × 10~(-2) ìB/Mn; remain magnetization of 0.6055 × 10~(-3)ìB/Mn and magnetic energy product of 1.53823 ìBGS/Mn. The ferromagnetic behavior can be attributed to the ferromagnetic exchange induced by bondage p-type carriers.