On Some Surprising Effective Exchange InteractionsWhen: Wednesday, March 26, 2014 at 3:00 pm
Where: DA 114
Speaker: Alberto André Saúl
Organization: CINaM/CNRS - Mareseille, France, Senior Research Scientist, MIT
Sponsor: Physics Colloquium
The interpretation of the magnetic properties of newly synthesized compounds very frequently relies in model Hamiltonians (Ising, Heisenberg , ANNI, …) whose justification is very often based on rather qualitative crystallographic and chemical considerations. In this framework, the determination of the dominant magnetic couplings in a crystal, based on the sole consideration of the geometry of a compound (distances separating the magnetic centers or arrangement of coordination polyhedra) is often incomplete and even misleading. Theoretical analysis of the electronic structure of these crystals by methods based in Density Functional Theory (DFT) often appears as the only mean to remove any ambiguity about the microscopic origin of their interactions. In this seminar, I will present our studies on a few compounds with rather unexpected magnetic properties.
Host: Assistant Professor Adrian Feiguin