论文部分内容阅读
Glassy magnetic behavior and exchange bias phenomena are observed in single phase Mn_3O_4 nanoparticles.Dynamics scaling analysis of the ac susceptibility and the Henkel plot indicate that the observed glassy behavior at low temperature can be understood by taking into account the intrinsic behavior of the individual particles consisting of a ferrimagnetic(FIM) core and a spin-glass surface layer.Field-cooled magnetization hysteresis loops display both horizontal and vertical shifts.Dependence of the exchange bias field(H_E) on the cooling field shows an almost undamped feature up to 70 kOe,indicating the stable exchange bias state in Mn_3O_4.H_E increases as the particle size decreases due to the higher surface/volume ratio.The occurrence of the exchange bias can be attributed to the pinning effect of the frozen spin-glass surface layer upon the FIM core.
Glassy magnetic behavior and exchange bias phenomena are observed in single phase Mn_3O_4 nanoparticles. Dynamics scaling analysis of the ac susceptibility and the Henkel plot indicate that the observed glassy behavior at low temperature can be understood by taking into account the intrinsic behavior of the individual particles. of a ferrimagnetic (FIM) core and a spin-glass surface layer. Field-cooled magnetization hysteresis loops display both horizontal and vertical shifts. Dependence of the exchange bias field (H_E) on the cooling field shows an almost undamped feature up to 70 kOe , indicating the stable exchange bias state in Mn_3O_4.H_E increases as the particle size decrease due to the higher surface / volume ratio. the occurrence of the exchange bias can be attributed to the pinning effect of the frozen spin-glass surface layer upon the FIM core.