Quenched zinc ferrite is ferrimagnetic, annealed ferrite paramagnetic at 300°K. Although annealed zinc ferrite has a lambda‐type heat capacity transition at about 9.5°K, quenched zinc ferrite retains only elementary vestigia of this transition. A similar effect exists in Li0.05Zn0.90Fe2.05O4in which the transition temperature is slightly lowered relative to that of zinc ferrite. This temperature shift does not appear to exist for Ni0.1Zn0.9Fe2O4. The magnetic entropy at 300°K is essentially unaltered by lithium substitution or thermal history.