Abstract
The magnetic structure factors of MnAlGe (space groupP4/nmm) measured with polarised neutrons have been expressed in terms of the magnetic moment of the Mn atom (site symmetry tetrahedral with tetragonal distortion), the Bessel transforms 〈j n〉 of the Mn radial functions and the fractional occupancies of the moment density in the various crystal field orbitals. The measured structure factors were least-squares fitted with the theoretical expression involving 〈j n〉 appropriate to the Mn0, Mn+ and Mn2+ atoms. The best fit was got using Mn0 transforms, yielding 1·45µ B as the Mn magnetic moment. The fractional occupancies of the moment density in the crystal field orbitalsA 1g,B 1g E g andB 2g were obtained. This analysis shows the magnetic moment to be highly non-spherical with a large fractional occupancy (38%) in theA 1g orbital directed along the tetragonal axis while the fractional occupancies ofB 1g andB 2g are found to be 31% and 30% respectively. The fractional occupancy of the moment in theE g orbital directed towards the Ge and Al atoms is very low (1%). The spatially averaged moment density of Mn in MnAlGe is more diffuse than that of Mn I and Mn II in isostructural Mn2Sb.
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Research Associate from the University of Bombay.
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Paranjpe, S.K., Tendulkar, S.R., Madhav Rao, L. et al. Non-spherical magnetic moment in MnAlGe. Pramana - J Phys 3, 355–362 (1974). https://doi.org/10.1007/BF02846630
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DOI: https://doi.org/10.1007/BF02846630