Proceedings of the thirteenth annual meeting of the Arizona Society for electron microscopy and microbeam analysis held in Tucson, Arizona, March 26-27, 1992

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 266 KB
• Volume: 22
• Category: Article
• ISSN: 1059-910X
• DOI: 10.1002/jemt.1070220410

✦ Synopsis

AZ 85721. "EM analvses of magnetic particles used in particulate recording media. High performance particulate magnetic recording media require consistent and uniform magnetic characteristics over the entire media surface. The properties of magnetic recording media can be influenced by the particle characteristics, such as shape, size and presence of defects. In this study, characterization of iron based metal particles (coercivity, H, = 1500 Oe; magnetization, M, = 120 emu/gm) and cobalt-modified iron oxide particles (H, -600 Oe, M, -75 emu/gm) were carried out using transmission electron microscopy (TEM).

In the case of cobalt-modified iron oxide particles, the effect of attrition milling in a liquid medium on particle characteristics was investigated. It was found from the micrographs that the acicular particles (length -0.34 pm, aspect ratio -7:l) were not damaged during the milling process. The micrographs of the particles also showed that there are some pores and irregularities at the surface. This may be due to the large material transport and the density change that take place in the solid-state reactions of the dehydration and reduction processes during particle synthesis.

Compared to the cobalt-modified iron oxide particles, the metal particles were smaller in size and had a more uniform surface. The length and aspect ratio of these particles were about 0.28 pm and lO:l, respectively. These particles contained an iron core of 120