Mechanical Alloying and Thermal Decomposition of (ZrO2)0.8-(ALPHA-Fe2O3)0.2 Powder for Gas Sensing Applications

BaMnS2 and Ba0.93Sr0.07MnS2 were prepared from the binaries and elements at 1000°C. Ba0.93Sr0.07MnS2 represents the limit of substitution in the Ba1-xSrxMnS2 solid solution and was characterized by single-crystal X-ray diffraction (orthorhombic, space group Pnma, a=7.109(2) ?, b=4.1069(13) ?, c=13.938(4) ?, V=407.0(2) ?3, Z=4), and wavelength dispersive X-ray spectroscopy. The compounds are isostructural, possessing a two-dimensional array of MnS4/2 tetrahedra with channels of Ba/Sr atoms separating the layers. BaMnS2 is antiferromagnetic with a suppressed moment at 300 K (TN>380 K). Ba0.93Sr0.07MnS2 is also antiferromagnetic but shows short-range magnetic correlations between 230 and 70 K. M versus H curves at 100 K showed a small hysteresis. The (Ba/Sr)2+ ions in Ba0.93Sr0.07MnS2 are shifted to one side of the interlayer channels relative to BaMnS2 and may be responsible for the anomalous magnetic behavior.