High frequency propagation of magnetic bubbles in dual conductor devices

Abstract

Garnet epitaxial films with an orthorhombic anisotropy and a 1.7 μm bubble diameter have been grown under strong compression on 〈110〉 oriented G.G.G. substrates. The bubble mobility in these films is about 60 m/s ⋅ Oe and the maximum velocity is about 50 m/s. Dual conductor circuits with an 8 μm period have been processed onto these films with a planar processing technology. It has been shown that a Poly Tetra Fluoro Ethylene spacer reduces strongly the influence of the mechanical stresses in the overlay on the magnetic properties of the strongly magnetostrictive epi-layer. This spacer is necessary for good propagation characteristics. At 6 MHz propagation margins of 14% have been observed at a linear current density of 2 mA/μm.