Magnetism of Ru and Rh thin films on Ag(001) substrate

TL;DR

This study investigates the magnetic properties of Ru and Rh thin films on Ag(001), revealing high magnetic moments at low coverage and explaining the effects of relaxation and alloying using the Stoner model.

Contribution

It demonstrates that first-principles calculations including relaxation and alloying can predict magnetism in Ru and Rh films, addressing previous experimental-theoretical discrepancies.

Findings

High magnetic moments in low-coverage Ru and Rh films (~2.49 and 2.00 μB)

Magnetic moments decrease with increased coverage

Relaxation increases and alloying decreases magnetic moments

Abstract

In a very recent x-ray magnetic circular dichroism experiment concerning with Ru and Rh impurities and metal films on Ag(001) substrate, no local magnetic momen ts were displayed in direct contradiction with previous theoretical works. It is thought that there can be three main reasons for this inconsistency: relaxation, alloying and many-body effects. Some of the above-mentioned systems are studie d by using a first-principles method in which relaxation and alloying are taken into account, even so magnetism is still obtained. For low-coverage systems, hig h magnetic moments in both Ru ($\sim$ 2.49 $\mu_{B}$) and Rh ($\sim$ 2.00 $\mu_{B}$) are obtained. Naturally, as the coverage is increased the magnetic moments are approached to zero. Also, it is noticed that the relaxation distances are in creased by magnetism, which in turn is decreased by alloying. The behavior of th e magnetic properties is explained in terms of Stoner model.