Observation of Antiferromagnetism in Marokite CaMn2O4

✍ Scribed by Christopher D. Ling; J.J. Neumeier; Dimitri N. Argyriou

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 512 KB
• Volume: 160
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2001.9214

✦ Synopsis

Marokite (CaMn 2 O 4 ) has been identi5ed as a low-level impurity in the solid-state synthesis of Ca 1؊x La x MnO 3 perovskites in the low-x region. In order to properly isolate the complex magnetic behavior of these important perovskites, the lowtemperature magnetic structure and properties of marokite are determined and reported. All Mn ions are in the high-spin 3 ؉ oxidation state. Jahn+Teller-distorted MnO 6 octahedra share both edges and vertices in a three-dimensional network, through which various exchange mechanisms cooperatively give rise to antiferromagnetic Mn 3 ؉ spin order. The magnetic order is evidenced below T N ‫؍‬ 220 K by a peak in the magnetic susceptibility and the appearance of symmetry-lowering magnetic Bragg re-6ections in neutron di4raction.