Patent · US Expired

Barium ferrite magnetic powder and magnetic recording medium containing the same

US4778734A · kind A · utility

13Cited by
3References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 1, 1988
Grant dateOct 18, 1988
Priority date
Expiry dateFeb 1, 2008

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/257
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A hexagonal magnetoplumbite-type barium ferrite magnetic powder represented by the following formula EQU BaO.n(Fe.sub.12-x-y-z M.sub.x.sup.1 M.sub.Y.sup.2 Zn.sub.z O.sub.18-.alpha.) wherein M.sup.1 represents at least one metal element selected from Co, Ni, Cu, Mg, and Mn; M.sup.2 represents at least one metal element selected from Zr, Ti, and Ge; n is a number of from 0.8 to 1.0; x is a number of from 0.1 to 2.5; y is a number of from 0.1 to 1.5; x is a number of from 0.1 to 1.5; and .alpha. is 1/2(3-m)(x+y+z) in which m is a number of less than 3 and represents an average atomic valence of M.sup.1, M.sup.2 and Zn. The said hexagonal magnetoplumbite-type barium ferrite is useful for a magnetic recording medium.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.