Physical properties including magnetic susceptibility, room-temperature electrical resistivity, thermal conductivity, heat capacity, and thermal expansion are reported for high quality single-crystal samples of marokite CaMn2 O4. We determined that CaMn2 O4 is highly electrically insulating and exhibits long-range antiferromagnetic order below TN =217.5/0.6 K with easy axis along a. Anisotropic thermal expansion, similar to that of crystallographically layered materials, is observed, suggesting that the crystal structure of CaMn2 O4 is also assembled from previously undescribed layers. An extensive thermodynamic study of the antiferromagnetic transition was undertaken resulting in a heat-capacity critical exponent =0.082/0.007 and calculated pressure derivative d TN /dP=5.154/0.174 K/GPa.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Mar 3 2009|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics