A note on crystal formation in the metallic oxides

The paper describes the behaviour of N23+O3 when heated to the usual sintering temperatures with M2+O in the following combinations: N3+ = B3+, M2+ = Ni2+; N3+ = Fe3+, M2+ = Sr2+ and Ba2+; N3+ = In3+, M2+ = Co2+, Zn2+, Ca2+ and Ba2+; N3+ = Y3+, M2+ = Cu2+, Zn2+, Mn2+, Cd2+, Sr2+ and Ba2+; N3+ = Gd3+, M2+ = Ni2+, Ca2+, Sr2+ and Ba2+; and N3+ = La3+, M2+ = Cu2+, Zn2+, Mn2+, Cd2+, Sr2+ and Ba2+. In many instances, the components would not react, leaving unmixed phases; when reaction did occur, no cubic spinels were formed. The relative size of the trivalent and divalent ion is apparently important for the formation of solid solutions. A double trivalent substitution of both Sc3+ and Al3+ for Fe3+ in nickel ferrite did not yield a compensation point. The relation to ferrite applications is included.