Thin film head having negative magnetostriction

• US 4,242,710 A
• Filed: 01/29/1979
• Issued: 12/30/1980
• Est. Priority Date: 01/29/1979
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hempstead, Robert D., Money, James B.
• Primary Examiner(s): Wolff, John H.
• Application Number:
  US06/007,274
• Time in Patent Office: 701 Days
• Field of Search: 360/113, 360/111, 360/123, 360/125, 360/126-127, 338/32 R, 324/249
• US Class Current: 360/328
• CPC Class Codes: G11B 5/3109 Details G11B5/3103 takes precedence

Abstract

A thin film inductive head is formed with nickel-iron binary alloy or nickel-iron-X ternary alloy pole pieces characterized by negative magnetostriction having a saturation magnetostriction coefficient in the range of -1×10^-6 to -5×10^-6.

Claims

1. A thin film magnetic head assembly consisting:

first and second magnetic pole pieces formed as unitary thin film layers said first pole piece being deposited directly on a substrate

insulating material disposed between and separating said pole pieces;

planar conductive coils in a substantially planar array disposed within said insulating material;

said pole pieces being formed from a magnetic material characterized by negative magnetostriction.

2. A thin film magnetic head assembly as in claim 1, wherein said magnetic material of said pole pieces has a saturation magnetostriction coefficient in the range of -1×

10^-6 to -5×

10^-6.

3. A thin film magnetic head assembly as in claim 1, wherein said magnetic pole pieces are formed from a nickel-iron composition, with a nickel to iron ratio in the range of 81:

19 to 84;

16 by weight.

4. A thin film magnetic head assembly as in claim 1, wherein said magnetic pole pieces are formed from a ternary nickel-iron-X alloy, having a saturation magnetostriction coefficient in the range of -1×

10^-6 to -5×

10^-6.

5. A thin film magnetic head assembly, as in claim 4, wherein the material X is from the group including boron, carbon, silicon, phosphorous, titanium, vanadium, chromium, cobalt, copper, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, and mercury.