Magnetic multilayer film and magnetoresistance element

US5510172A · kind A · utility

Assignee

• TDK CORPORATION · JP

Inventors

• Satoru Araki · Chiba, JP
• Daisuke Miyauchi · Tokyo, JP

Key dates

• Filing date: Jun 23, 1993
• Grant date: Apr 23, 1996
• Expiry date: Jun 23, 2013

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/24975
• WIPO field: Micro-structural and nano-technology
• WIPO sector: Chemistry

Abstract

A magnetic multilayer film having magnetoresistance (MR) is prepared by depositing at least two magnetic thin films having different coercive forces while interposing a non-magnetic thin film therebetween. A first magnetic thin film having a lower coercive force has a squareness ratio SQ.sub.1 and a thickness t.sub.1, a second magnetic thin film having a higher coercive force has a squareness ratio SQ.sub.2 and a thickness t.sub.2, and the non-magnetic thin film has a thickness t.sub.3. A first form of the invention requires 4 .ANG..ltoreq.t.sub.2 <30 .ANG., 20 .ANG.<t.sub.1 .ltoreq.200 .ANG., t.sub.1 >t.sub.2, t.sub.3 .ltoreq.200 .ANG., 0.7.ltoreq.SQ.sub.1 .ltoreq.1.0, and 0.1.ltoreq.SQ.sub.2 .ltoreq.0.8, thereby achieving a magnetic multilayer film which shows a great MR ratio of several percents under an external magnetic field of several Oe, an excellent rise across zero magnetic field and heat resistance. A second form of the invention requires 4 .ANG.<t.sub.2 <20 .ANG., 5 .ANG.<t.sub.1 .ltoreq.20 .ANG., t.sub.1 <t.sub.2 and 32 .ANG.<t.sub.3 <50 .ANG., thereby achieving a magnetic multilayer film which is increased in MR ratio, MR slope between -50 Oe and +50 Oe, and high-freq…