Adjacent element magnetic coupling in continuous film memories

Experimental measurements demonstrate that in magnetic film memory geometries employing continuous planar films, film strips, or plated wires, word line to word line coupling is enhanced by the presence of the intervening magnetic material. Rotation of the magnetization under a word line neighboring a driven word line can be several times greater than that which would occur for mechanically defined elements. Appropriately placed keepers can drastically reduce this interaction. The interaction is most severe for thick, low HKfilm material and tight element spacing. Theoretical analysis and experimental results show that for typical keepered geometries, the magnetic field inside the magnetic material decreases approximately exponentially with the distance from the driven word line. The attenuation constant α can be conveniently determined from the material parameters and element dimensions by calculating the series and shunt reluctance per unit length.