Marokite (CaMn2O4) has been identified as a low-level impurity in the solid
-state synthesis of Ca1-xLaxMnO3 perovskites in the low-x region. In order
to properly isolate the complex magnetic behavior of these important perovs
kites, the low-temperature magnetic structure and properties of marokite ar
e determined and reported. All Mn ions are in the high-spin 3 + oxidation s
tate. Jahn-Teller-distorted NIMO, octahedra share both edges and vertices i
n a three-dimensional network, through which various exchange mechanisms co
operatively give rise to antiferromagnetic Mn3+ spin order. The magnetic or
der is evidenced below T-N = 220 K by a peak in the magnetic susceptibility
and the appearance of symmetry-lowering magnetic Bragg reflections in neut
ron diffraction. (C) 2001 Academic Press.