Nuclear magnetic resonance at up to 10.1 GPa pressure detects an electronic topological transition in aluminum metal.

High-sensitivity (27)Al nuclear magnetic resonance (NMR) measurements of aluminum metal under hydrostatic pressure of up to 10.1 GPa reveal an unexpected negative curvature in the pressure dependence of the electronic density of states measured through shift and relaxation, which violates free electron behavior. A careful analysis of the Fermiology of aluminum shows that pressure induces an electronic topological transition (Lifshitz transition) that is responsible for the measured change in the density of states.

Co dimers on hexagonal carbon rings proposed as subnanometer magnetic storage bits.

It is demonstrated by means of density functional and ab initio quantum chemical calculations, that transition-metal-carbon systems have the potential to enhance the presently available area density of magnetic recording by 3 orders of magnitude. As a model system, Co2 benzene with a diameter of 0.5 nm is investigated.

Transition metal dimers as potential molecular magnets: A challenge to computational chemistry.

Dimers are the smallest chemical objects that show magnetic anisotropy. We focus on 3d and 4d transition metal dimers that have magnetic ground states in most cases. Some of these magnetic dimers have a considerable barrier against re-orientation of their magnetization, the so-called magnetic anisotropy energy, MAE.