Title :
Magnetic Properties of Epitaxial Co-Evaporated Fe:MgO Anti-Granular Films
Author :
Rummey, M. ; Fleet, L.R. ; Hing, H. ; Zhang, X. ; Hirohata, A.
Author_Institution :
Dept. of Electron., Univ. of York, York, UK
Abstract :
MR effects in epitaxial Fe:MgO anti-granular systems, which consist of MgO nanoparticles in an Fe matrix, have been studied at room temperature. Fe and MgO were co-evaporated on MgO(001) substrate in the ratio of Fe:MgO = 4:1, 3:1, and 2:1. The samples were annealed for up to 5 h inducing a uniaxial anisotropy. The saturation magnetization of the samples was found to be up to 20% greater than the value for bulk Fe. This is induced by a moment enhancement at the Fe/MgO interfaces. The corresponding magnetoresistance shows strong isotropic behavior with anisotropic components up to ±0.09% for a magnetic field applied along the hard axis. Very strong uniaxial anisotropy is observed with a hysteresis loop squareness of up to 0.97 for the annealed samples.
Keywords :
annealing; granular materials; interface magnetism; iron; magnesium compounds; magnetic anisotropy; magnetic epitaxial layers; magnetic hysteresis; magnetic moments; magnetic particles; magnetoresistance; nanofabrication; nanomagnetics; nanoparticles; vacuum deposition; MgO; MgO(001) substrate; MgO:Fe; annealing; antigranular films; epitaxial coevaporation; hysteresis loop squareness; interface magnetism; magnetic moment; magnetic properties; magnetoresistance; nanoparticles; saturation magnetization; temperature 293 K to 298 K; time 5 h; uniaxial anisotropy; Annealing; Iron; Magnetic tunneling; Perpendicular magnetic anisotropy; Saturation magnetization; Tunneling magnetoresistance; Epitaxial layers; granular systems; tunneling magnetoresistance;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2012.2198456
