| 摘要 |
<p>The cpds for use in the prodn of magnetic tapes, oxidation/dehydrogenation catalysts and semiconducting materials have the formula:- They are prepd by oxidising at 250-400 degrees C, with air or oxygen, an oxide mix of Fe and Cr contg. divalent Fe and formed of crystallites 10000A in size. Pref. the oxide mix is formed of substd. magnetites of formula:- or solid solns of gamma Cr2O3 in iron chromite of formula:-.</p> |
