A Knudsen cell approach for the molecular beam epitaxy of the heavy fermion compound YbRh[formula omitted]Si[formula omitted

Abstract

Thin films of the heavy fermion compound YbRh2Si2 were grown by molecular beam epitaxy on Ge (001) substrates using effusion cells. As-grown YbRh2Si2 thin films were characterized by a wide range of characterization techniques. X-ray diffraction yields a set of (00l) peaks, demonstrating epitaxial growth along the crystallographic c direction, with a lattice parameter c ranging from 9.84Å–9.95Å. The electrical resistivity shows behavior similar to YbRh2Si2 films grown previously using electron-beam evaporators for Rh and Si. The most stoichiometric sample appears to have the highest quality: It has the highest intensity ratio of the YbRh2Si2 (004) diffraction peak to the Ge (004) peak, the highest R(10 K)/R(2.3 K) ratio, a smallest surface roughness, and only a small density of surface defects.