Molecular beam epitaxy growth of nonmagnetic Weyl semimetal LaAlGe thin film

TL;DR

This paper demonstrates a reliable method for growing high-quality LaAlGe thin films, a non-magnetic Weyl semimetal, using molecular beam epitaxy, and characterizes their structural and electrical properties.

Contribution

It introduces a detailed MBE growth process for LaAlGe thin films and provides comprehensive structural and electrical characterizations of the films.

Findings

High-quality, uniform LaAlGe films were grown on silicon substrates.

The films exhibit semimetallic behavior with electron-dominated conduction.

Temperature-dependent resistivity aligns with electron-phonon scattering models.

Abstract

Here, we report a detailed method of growing LaAlGe, a non-magnetic Weyl semimetal, thin film on silicon(100) substrates by molecular beam epitaxy and their structural and electrical characterizations. 50 nm thick LaAlGe films were deposited and annealed for 16 hours in situ at a temperature 793 K. As-grown high-quality films showed uniform surface topography and near ideal stoichiometry with a body-centered tetragonal crystal structure. Temperature-dependent longitudinal resistivity can be understood with dominant interband s-d electron-phonon scattering in the temperature range 5-40 K. Hall measurements confirmed the semimetallic nature of the films with electron dominated charge carrier density near 7.15*10^21 cm^-3 at 5 K.