Accession Number:

ADP012273

Title:

Microstructure and Magnetic Properties of Co-CoO Nanocomposite Films

Descriptive Note:

Conference proceedings

Corporate Author:

CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF MATERIAL SCIENCE AND ENGINEERING

Personal Author(s):

Report Date:

2001-04-01

Pagination or Media Count:

6.0

Abstract:

The effect of exchange anisotropy on nanosize Co particles was studied in Co-CoO nanocomposite thin films for possible applications for magnetic storage media. XRD analyses showed nanosize hcp Co particles and 111 textured CoO phase. A broken columnar structure was observed in cross-section TEM images. Very large room temperature coercivity 1 kOe was observed and believed to be doe to a shape effect and possible local exchange coupling. Large exchange anisotropy at low temperatures and linear type temperature dependence were explained by finite size effects and thermal relaxation of the CoO particles. A slow decrease of thermoremanent moment TRM with temperature and large TRM at room temperature indicated that the exchange anisotropy significantly modified the anisotropy energy barrier of the Co crystallites in the CoO matrix. The results indicated that the exchange anisotropy could be used to stabilize nanosize ferromagnetic particles.

Subject Categories:

  • Properties of Metals and Alloys
  • Electricity and Magnetism
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE