| The magnetoresistance arising from the Ferromagnetic(FM) multilayered systems have great been applied in the field of the magnetic memorization and the magnetic sensor. Recently, the exchange bias has been found in the FM/AFM systems, and it can enhance the magnetoresistance, so the FM/AFM systems have been aroused to be considerable interests.Based on Monte Carlo method, the effect of nonmagnetic dilution on the exchange bias and the coercivity is studied in FM/AFM bilayers and FM/AFM mixed monolayer. Besides, the temperature dependence of the exchange bias and coercivity in FM/AFM bilayers and FM/AFM mixed monolayer is investigated by changing nonmagnetic doping concentration and doping mode. The main content is described as follows:1 By changing diluted concentration, the characteristic of exchange bias is discussed in FM/AFM bilayers by Monte Carlo method. The simulative results show that the exchange bias in FM/AFM bilayers can be enhanced significantly by substituting nonmagnetic atoms into the AFM layers. And there is a maximum in the sketch of exchange bias as a function of the diluted concentration, i.e. the exchange bias firstly increases then decreases with increasing concentration of dilution at the same temperature. Besides, the maximum of the exchange bias occurs at lower concentration for the higher temperature. These are agreement with the results of Phys. Rev. Lett. 96 117204(2006). The cause of these results is that the spin distributing and the magnetic domain structure are greatly changed with varying diluted concentration. The exchange bias approaches maximum when the positive magnetic domain and the negative one form the connected network structure. In addition, at the same concentration of dilution, by comparing the results of the random and regular dilution, we find that both the exchange bias are more increased by the regular dilution than by random dilution for the FM/AFM bilayers, which shows that the characteristic of exchange bias in FM/AFM... |
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