Title :
Garnet films for 64 Mb bubble memory devices
Author :
Hosoe, Y. ; Imura, R. ; Suzuki, R. ; Ikeda, T.
Author_Institution :
Hitachi Ltd., Tokyo, Japan
fDate :
9/1/1989 12:00:00 AM
Abstract :
Garnet films of (BiSmLu)3(FeAl)5O12 supporting 0.4-0.45-μm diameter bubbles have been studied for use in 64-Mb bubble memory devices. Using CaMgZr:GGG substrates with a large lattice constant (12.498 Å), the anisotropy energy Ku can be increased to 2.5×105 erg/cm3 by increasing the Sm content in the film. Consequently, the bubble diameter can be reduced to 0.4-0.45 μm, keeping the effective anisotropy field (Hk-4πMs) at more than 1500 Oe. For the films on GGG with a Ku value of about 1.8-105 erg/cm3, the value of Hk and/or the film thickness must be decreased compared to the values for films on CaMgZr:GGG in order to reduce the bubble diameter to less than 0.45 μm
Keywords :
bismuth compounds; garnets; magnetic bubble memories; magnetic thin films; (BiSmLu)3(FeAl)5O12 garnet films; 0.4 to 0.45 micron; 64 Mbit; CaMgZr-GdGG; CaMgZr-GdGa5O12; anisotropy energy; anisotropy field; bubble diameter; lattice constant; Anisotropic magnetoresistance; Bismuth; Garnet films; Iron; Lattices; Magnetic resonance; Spectroscopy; Strips; Substrates; Wavelength measurement;
Journal_Title :
Magnetics, IEEE Transactions on
