Magnetic Bubble/Bloch Line Memory
Enhancement Effect of Hydrogen Atmosphere Annealing on Anisotropy Field Change in Ion Implanted Garnet Films
1984 Volume 8 Issue 2 Pages 153-156
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1984 Volume 8 Issue 2 Pages 153-156
Annealing of ion-implanted garnet films in hydrogen atmosphere has been studied. It was found that the anisotropy field change, Δ(Hk-4πMs), for He+ implanted films was enhanced after the annealing. Δ(Hk-4πMs) for H2+ implanted films annealed in hydrogen atmosphere was kept larger than for samples annealed in air. Since there was little effect on Hk-4πMs for unimplanted bubble layers after the annealing, this enhancement arises from implanted layers. Lattice strain, Δa/a, was nearly equal to that for samples annealed in air. The enhancement of Δ(Hk-4πMs) disappeared with annealing in air above 350°C It is well known that H+ implantation shows excess contribution to ΔHk which is not attributable to simple magnetostriction but rather to the chemical effect. The enhancement Δ(Hk-4πMs) by hydrogen atmosphere annealing was similar to this “hydrogen chemical effect”. 0.5 μm bubble propagation was studied using He+ implanted films (1.8 eV/Å3 damage level) annealed in hydrogen gas for one hour at 300°C The propagation margins were measured around 2.5 μm pitch “good” loops. The minimum rotating field was 50 Oe and bias margin was 40 Oe at 65 Oe rotating field.
