The spinels CoRh2O4 and Co2RhO4

Polycrystalline CoRh₂O₄ and Co₂RhO₄ are cubic, spinel-type double oxides, S.G. Fd3m (No. 227), Z = 8. For CoRh₂O₄, $\text{a}\text{= 8.4992(1)}\text{A}\text{?}$, $\text{U = 613.95(3)}\text{A}\text{?}{}^3$, D_X = 7.11 Mgm^?3, $\text{x}\text{= 0.257}$, Co in 8(a) positions, R = 0.043. For Co₂RhO₄, $\text{a}\text{= 8.299(2)}\text{A}\text{?}$, $\text{U = 517.6(5)}\text{A}\text{?}{}^3$. D_X = 6.62 Mgm^?3, $\text{x}\text{= 0.261}$, half the Co content in 8(a) positions, R = 0.041. IR absorption band frequencies for both spinels are included.