Magnetic devices utilizing garnet epitaxial material

Claim 1

MEMORY DEVICE COMPRISING A SUBSTRATE SUPPORTING AT LEAST A FIRST EPITAXIAL LAYER, THE SAID LAYER BEING CAPABLE OF EVIDENCING UNIAXIAL MAGNETIC ANISOTROPY CAPABLE OF SUPPORTING LOCAL ENCLOSED REGIONS OF MAGNETIC POLARIZATION OPPOSITE TO THAT OF SURROUNGING MATERIAL AND PROVIDED WITH FIRST MEANS FOR MAGNETICALLY BIASING SAID LAYER TO STABILIZE SAID REGIONS, SECOND MEANS FOR POSITIONING SUCH OPPOSITELY POLARIZED LOCAL AND ENCLOSED REGIONS, AND THIRD MEANS FOR PROPAGATING SUCH LOCAL REGIONS, SAID MATERIAL BEING OF THE GARNET STRUCTURE, CHARACTERIZED IN THAT THE COMPOSITION OF THE SAID MATERIAL OF THE SAID FIRST LAYER MAY BE REPRESENTED BY THE ATOM FORMULA (Y,LA,LU,BI)3-A-BRAMABFE5-C-D-E(AL,GA)C (SI,GE)DVEO12, WHERE R IS ONE OR A COMBINATION OF PR, ND, SM, EU, GD, TB, DY, HO, ER, TM AND YD AND WHERE R IS AT LEAST 50 PERCENT EU, M IS AT LEAST ONE OF CA, SR AND CK, A IS FROM 0.03-0.2 FOR ALL EXCEPT TB, DY AND HO FOR WHICH A IS FROM 0.03-0.1, B IS FROM 0.5-15, C IS FROM 0-5.5, D IS FROM 0.5-1.3, AND E IS FROM 0-0.5 AND HEREIN D IS AT LEAST EQUAL TO C+E (I.E., AT LEAST ONE-HALF OF THE IONS REPLACING IRON ARE SILICON AND/OR GERMANIUM), THE SAID FIRST LAYER HAVING A MAGNETOSTRICTIVE VALUE WHICH IS OF NEGATIVE SIGN, THE SAID FIRST LAYER AND SUBSTRATE BEING MISMATCHED IN LATTICE PARAMETER BY AN AMOUNT EXPRESSED AS A DIFFERENTIAL VALUE OF THE LATTICE PARAMETER AO OF FROM 0.005 TO 0.017 WITH THE VALUE OF THE SAME LATTICE PARAMETER BEING LARGER FOR THE SUBSTRATE SO AS TO RESULT IN STRAIN INDUCED ANISOTROPY RESULTING IN POLARIZATION DIRECTION NORMAL TO THE PLANE OF THE SAID FIRST LAYER, THE TOTAL SAID ANISOTROPY BEING AT LEAST 50 PERCENT DUE TO STRAIN RESULTING FROM THE SAID MISMATCH IN THE LATTICE PARAMETER.