Magnetic bubbles

Ca is replaced by a rare-earth element, resulting in a distorted perovskite stmcture, which is essentially orthorhombic. Orthoferrites, studied extensively in the early 1970s as potential data storage materials based on magnetic bubble domains (10), have been largely replaced by the garnet materials (see... 

A. H. Bobeck and E. Della Torre, Magnetic Bubbles, North Holland Pubhshing Co., Amsterdam, the Nethedands, 1979. 

Garnets are important gems, abrasives, microwave systems components, magnetic bubble memories, and laser hosts. For the latter, yttrium aluminum garnet is the most important. It also plays an important role in aircraft turbines where it forms a protective coating on the turbine blades. 

Figure 9.11 Magnetic bubble memory schematic domains of reversed polarity (bubbles) are induced in the thin ferromagnetic garnet film.

Data storage via magnetic bubble memories used thin films of ... 

Important is the use of light rare earth elonents for production of hard magnetic materials. Most prominent are alloys of samarium with cobalt in the atomic ratio 1 5 or 2 17. It may also be assumed that in further development of these materials on a larger scale that praseodymium, neodymium, lanthanum and also individual heavy rare ecu h elements will be used to achieve particular effects. Interesting is the development of magnetic bubble memories based on gadolinium-galliiimrgarnets. 

Bobeck, A. H. Della Torre, E. "Magnetic Bubbles" North-Holland Amsterdam, 1975 p. 222. 

Chang, H. "Magnetic Bubble Technology" IEEE Press New York, 1975 p. 699. 

Aral, Shigeru presented at the First International Conference on Magnetic Bubble Materials, Santa Barbara, CA, January, 1980. 

Shift Registers with Submicron Magnetic Bubbles on Epitaxial Garnet Films. Presented at Intermag, Washington, D.C. See also Abstr. 26.5 in Abstr. Dig, for the same conference, 1973. 

Figure 7.10 Formation of magnetic bubbles (schematic). (After Blunt, 1983.)...

The progress of technology for the high-resolution fabrication of semiconductor and magnetic bubble devices has required sub-micron exposure techniques such as electron beam x-ray and deep UV. Although a number of papers have been published on electron beam resists, reaction mechanisms of electron resists are still largely unknown since few studies on reactive intermediates by means of direct measurements have been done in order to elucidate the reaction mechanisms. 

Cog3Gd17 sputtered sample can support magnetic bubbles... 

To date, the major uses of ytterbium have been in applied and fundamental research. The element and its compounds have been used in magnetic "bubble domain devices (ytterbium orthofemte). in phosphors to convert infrared to visible light, in lasers, and radioisotope 1fiCYb has found application in portable industrial and medical radiographic units. 

Rare earth substituted garnet films for magnetic bubble memory applications... 

Some of the problems seen with the commercially available polyimides such as limited shelf life,gelation and high ionic contamination are traceable to the raw materials themselves. A zone refining technique has been perfected for use with organic materials and these precursors have been used to synthesize ultrapure polyamic acids for IC device applications. The key feature of the synthesis is the use of solid ingots of the dianhydrides. Materials prepared by this technique show low metallic impurities and have been shown to be excellent film formers for a variety of applications. In particular a polyimide derived from PMDA-ODA has been used to passivate magnetic bubble devices. IR techniques coupled with electrical measurements have been used to optimize the cure conditions and a simple resist process has been defined to passivate these devices. Device performance compares well with conventional inorganic insulators. 

Magnetic bubble devices are high dens ity ynemory devices and use stored magnetic domains as storage areas. The key features of these devices are their simplicity of fabrication and use of Ni/Fe as device elements. The passivation of these devices is similar to corresponding IC devices except in the following ... 

A.Eschenfelder,"Magnetic Bubble Technology " Springer-Verlag (1980)... 

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