Characteristics of a Detection‐Propagation Structure for Bubble‐Domain Devices

A new chevron‐like structure which served both for detection and propagation of magnetic domains yielded 0.7‐mV sense signals from a 20‐μm period bubble device operated at 5‐mA detector current and 42‐Oe drive field rotating at 100 kHz. The sense signal — the voltage difference between the “one” and “zero” states — was superimposed on a 2.4‐mV peak‐to‐peak background. The detector‐propagation structure, made from the same 0.3‐μm thick permalloy as the propagation channel, consisted of a 51‐chevron column, the vertices of the chevrons being connected with a permalloy stripe. Typical resistance values were 60 Ω. The experimental results were obtained using an ion‐implanted film of Y0.9Eu1.9Yb0.2Al1.1Fe3.9O12. In comparison to thin‐film permalloy detectors operated at the same frequency the new structure provides not only more rugged devices but also superior signal voltage. Processing is simpler and faster. In addition, this design appears promising for high packing‐density applications because it permits s...