| 摘要 |
This invention relates to a process for stabilizing ferromagnetic chromium dioxide in respect of water and oxidizable organic compounds which it may contact in magnetic tapes. The process is applicable to a starting CrO2 having good magnetic properties, i.e. a coercive force not lower than about 400 Oersted, a maximum magnetic induction Bm not lower than about 2500 gauss, and a magnetic induction Br not lower than about 1600 gauss. The CrO2 is subjected to a heat treatment at a temperature ranging from 300 DEG to 390 DEG C. in the presence of a gas stream not exerting any oxidizing or reducing action on the compounds of trivalent, tetravalent and hexavalent chromium. Suitable gases are, for example, nitrogen, helium and argon. |
