公开(公告)号：US4224175A

公开(公告)日：1980-09-23

申请号：US29937

申请日：1979-04-13

申请人： Franco Montino ,  Ariello R. Corradi ,  Erminio Nonato

发明人： Franco Montino ,  Ariello R. Corradi ,  Erminio Nonato

IPC分类号： G11B5/706 ,  C01G49/06

CPC分类号： G11B5/70673

摘要： A process is disclosed for obtaining acicular magnetic particles of .gamma.-Fe.sub.2 O.sub.3 modified with Fe.sup.++ and Co.sup.++ ions. The product thus obtained and magnetic tapes containing said product are also disclosed. A suspension of acicular .gamma.-Fe.sub.2 O.sub.3 in an aqueous solution of soluble Fe.sup.++ and Co.sup.++ salts is prepared. NH.sub.3 is then added in such quantity that the molar ratioNH.sub.3 /(Fe.sup.++ +Co.sup.++)is between 2.1 and 3, and the whole mass is then heated up to 100.degree.-200.degree. C. When the molar ratio Fe.sup.++ /Co.sup.++ is greater than about 2.5, it is necessary to operate in the presence of a metered quantity of oxygen or of an oxygen-containing gas; when the ratio is smaller or equal to about 2.5, the presence of a metered quantity of oxygen is optional.

摘要翻译： 公开了一种获得用Fe ++和Co ++离子改性的γ-Fe2O3的针状磁性颗粒的方法。 由此获得的产品和含有所述产品的磁带也被公开。 制备针状γ-Fe2O3在可溶性Fe ++和Co ++盐水溶液中的悬浮液。 然后加入NH 3，使得NH 3 /（Fe +++ Co ++）的摩尔比在2.1和3之间，然后将整个物质加热至100℃-200℃。当Fe ++ / Co ++的摩尔比为 大于约2.5，需要在计量的氧气或含氧气体的存在下操作; 当该比例小于或等于约2.5时，计量的氧的存在是任选的。