GB1201610A - Improvements relating to magnetic storage elements - Google Patents

Abstract

1,201,610. Magnetic structures; magnetic storage arrangements. PLESSEY CO. Ltd. 16 Oct., 1967 [2 Nov., 1966], No. 49235/66. Heading H1H. [Also in Division H3] Each magnetic storage element in a matrix store (see Division H3) comprises a non-magnetic word conductor 11, Fig. 2, having continuous superposed films 12, 14 of anisotropic magnetic material with high and low coercivities, respectively, and an orthogonal digit conductor 15, the preferred magnetization direction of the high coercivity film 12 being substantially parallel to the word conductor, while the preferred magnetization direction of the low coercivity film 14 is inclined slightly, e.g. by 5 degrees, to the axis of the digit conductor. Writing is effected by applying pulses simultaneously to the word and digit conductors so as to establish " 0 " or " 1 " characterizing closed loop magnetizations 16, 17, Fig. 3, through the high and low coercivity films of a storage element. Non-destructive read out is effected by applying a pulse to a digit conductor sufficient to permit the magnetization of the low coercivity film to move away temporarily from its hard direction in which it is normally held by the field of the high coercivity film. Alternatively non-destructive read out is obtained by pulsing the word conductor, in either case the pulse being insufficient to disturb the magnetization of the high coercivity film. A non-magnetic film 13, e.g. of copper, may be interposed between the films to prevent diffusion between the films during the formation by deposition.