Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 33: Topical Session Theory meets Experiment II - Nanocomposites and Microstructure
MM 33.5: Vortrag
Mittwoch, 28. März 2012, 12:45–13:00, TC 006
Mechanical and magnetic properties of Mn–Pt compounds and nanocomposites — •Tomáš Káňa1 and Mojmír Šob2,3,1 — 1Institute of Physics of Materials, Brno, Czech Republic — 2Central European Institute of Technology, CEITEC MU, Brno, Czech Republic — 3Faculty of Science, Masaryk University, Brno, Czech Republic
An analysis of mechanical and magnetic properties of Mn–Pt compounds and nanocomposites is provided using DFT calculations. Adding manganese to platinum matrix reduces the bulk modulus and enhances the Young moduli E100, E111 as well as shear moduli (c11 - c12)/2 and c44. With increasing Mn content, the theoretical tensile strength is also enhanced and the corresponding maximum deformation is reduced. On the whole, manganese addition makes the Mn–Pt compounds softer, but increases their resistance to shape deformation. Many of these compounds may be considered as natural linear nanocomposites. We studied the magnetic configurations of recently found MnPt7 ordered structure and predict an antiferromagnetic state with spins altering along the [100] direction to be the ground state of this compound. We further studied Mn–Pt nanocomposites with the composition of MnPt15. Here an antiferromagnetic structure with spins altering along the [100] direction is the ground state of MnPt15 nanocomposite. The alternative ferromagnetic configurations of different MnPt15 nanocomposites exhibit the screening of magnetic moments of Mn atoms by flipping the moments induced on Pt atoms into the opposite direction. This indicates that the Mn spins can be coupled through the Pt atoms.