The Co2.50Sb0.50O4 spinel has been studied by neutron diffraction in the te
mperature range 10-90 K and at room temperature. The crystal and magnetic s
tructures were solved by the use of the Rietveld method. The cationic distr
ibution was determined to be (Co-1.00(2+))(8a) [Co0.503+Co1.002+Sb0.505+](1
6d), where 8a and 16d denote tetrahedral and octahedral crystallographic si
tes, respectively. A collinear ferrimagnetic structure with T-C approximate
to 60 K has been found. The obtained Values of magnetic moments of Co2+ io
ns at 10 K, mu(8a)(Co2+) = 2.6 mu(B) and mu(16d) (Co2+) = 2.9 mu(B), are sm
aller than expected and we discuss this result. (C) 2000 Elsevier Science B
.V. All rights reserved.