Molecular spin-probe sensing of H-mediated changes in Co nanomagnets.

The influence of hydrogen on magnetization is of substantial interest to spintronics. Understanding and controlling this phenomenon at the atomic scale, in particular in nanoscale systems, is crucial. In this study, we used scanning tunneling microscopy (STM) combined with a nickelocene molecule to sense the spin of a hydrogen-loaded nanoscale Co island grown on Cu(111).

Rationalization of the sub-surface segregation in nanoalloys of weakly miscible metals.

The origin of the stability of sub-surface precipitates in core-shell bimetallic nanoparticles is investigated from the perspective of atomic-size effects for systems where the core atoms have a size equal to, or lower than, the shell atoms. With the aim of providing more general assessments, a systematic study is proposed by considering three model systems combining weakly miscible metals: IrPd (negligible lattice mismatch, Δ/ = -1%), AuRh (moderate lattice mismatch, Δ/ = -7%) and AuCo (large lattice mismatch, Δ/ = -13%). The main driving forces for sub-surface segregation and the characteristic core morphologies are quantified from the combination of Monte Carlo and quenched molecular dynamics simulations.

How the hydrogen sorption properties of palladium are modified through interaction with iridium.

Hydrogen sorption (adsorption/absorption) in metals, in the form of thin films or nanoparticles, is a key process in the fields of energy storage and heterogeneous catalysis. Atomic hydrogen dissolved in the subsurface of a metal affects its surface atomic and electronic structures, and thereby its surface reactivity and catalytic properties. In addition, alloy effects modify both catalytic and hydrogen sorption phenomena.