Current-perpendicular-to-the-plane structure magnetoresistive element having the free and/or pinned layers being made of a granular film which includes an electrically conductive magnetic material and a dielectric material

• US 7,002,781 B2
• Filed: 08/29/2003
• Issued: 02/21/2006
• Est. Priority Date: 09/09/2002
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Sugawara, Takahiko
• Primary Examiner(s): Heinz, A. J.
• Application Number:
  US10/652,832
• Publication Number:
  US 20040052008A1
• Time in Patent Office: 907 Days
• Field of Search: 36032411-3242
• US Class Current: 360/324.11
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: G11B 5/3967 Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read G11B5/3906 takes precedence
• CPC Class Codes: H01F 10/3227 Exchange coupling via one or more magnetisable ultrathin or granular films
• CPC Class Codes: H01F 10/3259 Spin-exchange-coupled multilayers comprising at least a nanooxide layer [NOL], e.g. with a NOL spacer
• CPC Class Codes: H01F 10/3268 the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn

Abstract

A current-perpendicular-to-the-plane (CPP) structure magnetoresistive (MR) element includes a pinned magnetic layer made of a granular film. The granular film contains electrically-conductive magnetic crystal grains and an dielectric material. The dielectric material serves to thin the path of the sensing electric current in the pinned magnetic layer. Moreover, the sensing electric current concentrates at the magnetic crystal grains. A larger variation can be obtained in the voltage of the sensing electric current. The output of the CPP structure MR element can be enhanced.

Claims

1. A current-perpendicular-to-the-plane structure magnetoresistive element comprising:

a free magnetic layer;

a pinned magnetic layer; and

an electrically-conductive non-magnetic intermediate layer interposed between the free and pinned magnetic layers, wherein

at least one of the free and pinned magnetic layers is made of a granular film including an electrically-conductive magnetic material and a dielectric material.

2. The current-perpendicular-to-the-plane structure magnetoresistive element according to claim 1, wherein said electrically-conductive magnetic material contains crystal grains penetrating through the granular film from an upper joint surface to a lower joint surface.

3. The current-perpendicular-to-the-plane structure magnetoresistive element according to claim 2, wherein said crystal grains include at least one of cobalt and iron atoms.

4. The current-perpendicular-to-the-plane structure magnetoresistive element according to claim 3, wherein said dielectric material includes at least one of an oxide, a fluoride, a carbide and a nitride.