Technical trends in recording tape fine particles. A short review

Abstract

The development of magnetic particles with high coercivity has been required for higher density recording. In the history of magnetic particles, there have been several remarkable inventions produced almost every ten years, i.e., acicular 7-Fe203, Cr02, Co-adsorbed 7-Fe203, and metal particles, etc. Respective features and prospects are outlined. The size of 7-Fe203 is decreasing now to lower both audio and video noise. The appearance of Cr02 and the succeeding Co-adsorbed 7-Fe203 particles has brought about the growth of high performance audio and video recording. Metal particles were put to practical use for audio cassettes in 1979, and the Introduction of metal video tapes to the market is expected soon.

Modeling of the write and read back performances of hexagonal Ba-ferrite particulate media for high density tape recording

“…In 2007, 6.7 Gbit/in 2 areal density was achieved [1]. One of the causes for obtaining high areal densities was the application of densely packed hexagonal barium ferrite (h-BaFe) platelets, which have many advantages over metal particles (MP): chemical stability, high coercivity, and small particle size [2][3][4][5]. The small aspect ratio of the h-BaFe particles enables themselves to be easily aligned by applying of an external field during the coating procedure on the polymer tape [6].…”