公开(公告)号：AU6270973A

公开(公告)日：1975-05-22

申请号：AU6270973

申请日：1973-11-20

Applicant: IBM

Inventor： ROMANKIW LUBOMYR TARAS ,  THOMPSON DAVID ALEXANDER ,  BAJOREK CHRISTOPHER HENRY

IPC: G01R33/02 ,  G01R33/09 ,  G11B5/39 ,  G11C11/14 ,  H01F10/08 ,  H01F10/32 ,  H04R15/00 ,  G11B5/30

Abstract: 1450204 Magnetic heads INTER. NATIONAL BUSINESS MACHINES CORP 9 Nov 1973 [29 Dec 1972] 52064/73 Heading G5R [Also in Division H3] A magnetic sensing head comprises a unitary structure of a layer of magneto-resistive material 16 for sensing a magnetic field and an adjacent biasing layer 14 of permantly magnetized material to bias the layer 16 magnetically to a required operating range, layers 14 and 16 being in direct contact with one another. The layers 14 and 16 may be co-planar or laminated, with the direction of magnetization, arrow M h , of bias layer 14 parallel or perpendicular to the easy axis and sense current direction, arrow I, of layer 16. Layer 16 is of permalloy material, e.g. Ni-Fe, Ni-Co or Ni-Fe-Co, and the bias layer 14 may be of ferrite. Layers 14,16, may be evaporated, sputtered or electroplated on a substrate 12 with thicknesses of 200 to 2000 and 50 to 400 Šngstroms respectively. The bias may be established due to exchange or epitaxially coupled layers 14, 16, there being direct atomic contact between the layers. In another form the biasing layer 14 is a composite layer comprising exchange or epitaxially coupled films with a magnetically soft film atomically coupled to a magnetically hard film, e.g. Ni-Fe deposited on a Fe 2 O 3 , a Fe 2 O 3 on Ni-Fe, Co or Co-rich Ni-Co on vanadium or chromium, or binary Co-P. In a further form, the bias layer, or two bias layers with the sensing layer therebetween, is or are formed by preferentially oxiding one or both surfaces of a permalloy sensor strip. Alternatively such surfaces may have localized zones with a raised coercivity produced by chemical reaction with chlorides or sulphates, etching to roughen the surfaces, or by selective deposition of materials which exchange couple to the sensing layer. The combined sensing and bias layers may be surrounded by a magnetic shield (8) in a record head, Fig. 1 (not shown). The head may be used for reading tapes, discs, magnetic ink, or sheets capable of generating and transporting magnetic bubble domains.

公开(公告)号：DE2363123A1

公开(公告)日：1974-07-18

申请号：DE2363123

申请日：1973-12-19

Applicant: IBM

Inventor： BAJOREK CHRISTOPHER HENRY ,  ROMANKIW LUBOMYR TARAS ,  THOMPSON DAVID ALEXANDER

IPC: G01R33/02 ,  G01R33/09 ,  G11B5/39 ,  G11C11/14 ,  H01F10/08 ,  H01F10/32 ,  G11B5/12

Abstract: 1450204 Magnetic heads INTER. NATIONAL BUSINESS MACHINES CORP 9 Nov 1973 [29 Dec 1972] 52064/73 Heading G5R [Also in Division H3] A magnetic sensing head comprises a unitary structure of a layer of magneto-resistive material 16 for sensing a magnetic field and an adjacent biasing layer 14 of permantly magnetized material to bias the layer 16 magnetically to a required operating range, layers 14 and 16 being in direct contact with one another. The layers 14 and 16 may be co-planar or laminated, with the direction of magnetization, arrow M h , of bias layer 14 parallel or perpendicular to the easy axis and sense current direction, arrow I, of layer 16. Layer 16 is of permalloy material, e.g. Ni-Fe, Ni-Co or Ni-Fe-Co, and the bias layer 14 may be of ferrite. Layers 14,16, may be evaporated, sputtered or electroplated on a substrate 12 with thicknesses of 200 to 2000 and 50 to 400 Šngstroms respectively. The bias may be established due to exchange or epitaxially coupled layers 14, 16, there being direct atomic contact between the layers. In another form the biasing layer 14 is a composite layer comprising exchange or epitaxially coupled films with a magnetically soft film atomically coupled to a magnetically hard film, e.g. Ni-Fe deposited on a Fe 2 O 3 , a Fe 2 O 3 on Ni-Fe, Co or Co-rich Ni-Co on vanadium or chromium, or binary Co-P. In a further form, the bias layer, or two bias layers with the sensing layer therebetween, is or are formed by preferentially oxiding one or both surfaces of a permalloy sensor strip. Alternatively such surfaces may have localized zones with a raised coercivity produced by chemical reaction with chlorides or sulphates, etching to roughen the surfaces, or by selective deposition of materials which exchange couple to the sensing layer. The combined sensing and bias layers may be surrounded by a magnetic shield (8) in a record head, Fig. 1 (not shown). The head may be used for reading tapes, discs, magnetic ink, or sheets capable of generating and transporting magnetic bubble domains.