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Magnetic Film Memory

IP.com Disclosure Number: IPCOM000097913D
Original Publication Date: 1961-Sep-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Oguey, HJ: AUTHOR

Abstract

The bit-organized, coincident current memory employs thin magnetic film elements for storing binary bits of information. It avoids unwanted domain-wall motion due to half selects by applying drive fields to each element as shown.

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Magnetic Film Memory

The bit-organized, coincident current memory employs thin magnetic film elements for storing binary bits of information. It avoids unwanted domain-wall motion due to half selects by applying drive fields to each element as shown.

The critical switching curve 10 is for a thin magnetic film elements This exhibits a uniaxial, anisotropic characteristic defining opposite stable states, 0 and 1. Such states of remanent flux orientation are along an easy axis of magnetization 12. Rotational switching occurs in that area outside curve 10. Domain wall switching occurs within a region 14. A non-destructive region exists within an area defined by curve 16. Curve 16 defines the maximum fields which may be applied to such an element without causing permanent change in its magnetization.

A bias field Hdc is applied to all elements of a memory array directed in a downward hard direction. A half-select field Hx and a half-select field Hy are coincidently applied to a selected element having a similar magnitude. They define an acute angle (+alpha and -alpha) with respect to the hard direction of the element. The resultant field vector, applied by any one half select field Hx and Hy, falls within the area defined by curve 16 due to the bias Hdc.

The resultant field vector, applied by both half select fields Hx and Hy to a selected element, falls without the curve 10 approximately aligned with the hard direction of the element. Information is then stored by se...