Particulate compositions of ferromagnetic metal oxalates in the form of submicronic acicular particles, the preparation of same and application thereof

摘要

PCT No. PCT/FR86/00338 Sec. 371 Date Jul. 2, 1987 Sec. 102(e) Date Jul. 2, 1987 PCT Filed Sep. 30, 1986 PCT Pub. No. WO87/02033 PCT Pub. Date Apr. 9, 1987.The disclosed particulate composition of simple or mixed oxalate of ferromagnetic metals is characterized in that it is provided in the form of needle-shaped particles having a length comprised between 0.05 and 0.5 micrometer, with a proportion higher than 60% of particles having a length equal to the average length +/-0.1 mu m. and an acicular ratio higher than 3, said average length being comprised between 0.15 and 0.35 mu m; its preparation and its application are also disclosed.