title: Monte Carlo simulation of size, random field and temperature dependences of exchange bias in a core/shell magnetic nanoparticle.
abstract: By using Monte Carlo simulation on a ferromagnetic core/antiferromagnetic shell nanoparticle, we investigate in detail the exchange bias of the magnetic hysteresis as a function of both core radius and shell thickness, at low temperature. It is found that the exchange bias is very sensitive to the core radius and a small variation of the radius may lead to a big fluctuation of the bias. In a general tendency the exchange bias is enhanced by increasing shell thickness and decreasing core radius. The intrinsic correlation between the exchange bias and the spin configuration on the core-shell interface is demonstrated. We further investigate the dependence of the exchange bias on temperature and random field inside the nanoparticle, indicating a monotonic decreasing of the bias with the magnitude of random field and temperature, respectively.
authors.affiliation: Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, People's Republic of China. International Center for Materials Physics, Chinese Academy of Sciences, Shenyang, People's Republic of China.
authors.forename: M H
authors.initials: MH
authors.lastname: Wu
authors.forename: Q C
authors.initials: QC
authors.lastname: Li
authors.forename: J-M
authors.initials: JM
authors.lastname: Liu