This paper reports on the propagation and transfer of 1-μm bubbles in ion-implanted contiguous-disk devices, made by conventional photolithographic techniques. Bubble-propagation circuits are made of undulating patterns masked from implantation on a low-Q garnet film, which is grown on top of and exchange coupled with a medium-Q garnet film which supports the small bubbles. A double-garnet composite combines the good features of a medium-anisotropy storage layer to stabilize bubbles and, more importantly, of a small-anisotropy driving layer to ensure the creation of a planar magnetization layer by ion implantation. A fundamentally different propagation mechanism employing the charged walls around the implanted pattern edges is explained. The value of the charged walls is that they lend themselves to coarse-featured devices. Furthermore, they can be substantially lengthened to bridge a large gap between two propagation circuits to assist bubble transfer across that gap. We describe a switching gate employing such a bridging charged wall to transfer 1-μm bubbles across a 4-μm gap. Also included is an implantability analysis of several garnet compositions, pointing out why the ability to create a planar magnetization by implanting a single bubble layer diminishes as the bubble size approaches the 1–2-μm range. An implication is that a double-garnet composite, such as used in our contiguous-disk devices, may also be essential to other bubble devices (Permalloy bar and bubble lattice) for bubbles under 1–2 μm in diameter.

Experiments on disk and hole patterns in permalloy and in ion‐implanted garnet layers1..2 lead to the conclusion that the bubble domain propagation mechanism in the two structures is different. A ’’charged‐wall’’ model explains the ion‐implanted structure, and a single‐domain model relates the minimum propagation field to the garnet’s cubic anisotropy energy, in good agreement with experiment.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation G. S. Almasi, G. E. Keefe, K. D. Terlep; High‐Speed Sensing of Small Bubble Domains. AIP Conf. Proc. 1 January 1973; 10 (1): 207–211. https://doi.org/10.1063/1.2946891 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

This paper describes the fabrication and operation of a 52‐bit bubble domain memory chip designed to test the concept of on‐chip magnetic decoding. Access to one of the chip's four shift registers for the read, write, and clear functions is by means of bubble domain decoders utilizing the interaction between a conductor line and a bubble. All other functions are performed by a permalloy overlay driven by an external rotating field. The metallurgy consists of 200 Å evaporated permalloy for magnetoresistive sensors. 4000 Å electroplated permalloy for propagation etc., and 6000 Å electroplated copper for control lines.