title: Local observation of the site occupancy of Mn in a MnFePSi compound.
abstract: MnFePSi compounds are promising materials for magnetic refrigeration as they exhibit a giant magnetocaloric effect. From first principles calculations and experiments on bulk materials, it has been proposed that this is due to the Mn and Fe atoms preferentially occupying two different sites within the atomic lattice. A recently developed technique was used to deconvolve the obscuring effects of both multiple elastic scattering and thermal diffuse scattering of the probe in an atomic resolution electron energy-loss spectroscopy investigation of a MnFePSi compound. This reveals, unambiguously, that the Mn atoms preferentially occupy the 3g site in a hexagonal crystal structure, confirming the theoretical predictions. After deconvolution, the data exhibit a difference in the Fe L_{2,3} ratio between the 3f and 3g sites consistent with differences in magnetic moments calculated from first principles, which are also not observed in the raw data.
authors: School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia.
authors: M J
authors: MJ
authors: Neish
authors: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.|Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37212, USA.
authors: M P
authors: MP
authors: Oxley
authors: Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
authors: J
authors: J
authors: Guo
authors: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors: B C
authors: BC
authors: Sales
authors: School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia.
authors: L J
authors: LJ
authors: Allen
authors: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors: M F
authors: MF
authors: Chisholm