Experimental study of transport properties of Weyl semimetal LaAlGe thin films*

Rare earth compounds display diverse electronic, magnetic, and magneto-transport properties. Recently these compounds of the type RAlGe (R = La, Ce, Pr) have been shown to exhibit Weyl semimetallic behavior. In this work, we have grown and investigated the crystal structure, electronic, and magneto-transport properties of the Weyl semimetal LaAlGe thin films. As-grown films showed uniform surface topography and near ideal stoichiometry with a body-centered tetragonal crystal structure. The temperature dependence of longitudinal resistivity at different magnetic fields are discussed. Observations of magnetoresistances and the Hall effect at different temperatures and their evolution with magnetic field up to 6 T are also discussed with relevant mechanisms. We have observed positive unsaturated magnetoresistances, with a small quadratic contribution at low temperatures, which tends to saturate at higher fields. Our findings through various experimental investigations confirm the semi metallic nature of these films with an average charge carrier density of ~ 9.68×10²¹ cm^-3 at room temperature.