Anisotropic multiband magnetotransport in LaAg$_2$Ge$_2$ thin films

TL;DR

This study reports the growth and detailed magnetotransport characterization of LaAg$_2$Ge$_2$ thin films, revealing anisotropic multiband electronic behavior and magnetoresistance phenomena relevant to layered intermetallic conductors.

Contribution

It demonstrates the epitaxial growth of LaAg$_2$Ge$_2$ thin films and analyzes their anisotropic magnetotransport properties using a two-carrier model.

Findings

Positive magnetoresistance of 22.5% at 9 T

Dominant twofold anisotropy in angle-dependent magnetoresistance

Reproducible dip/peak features at characteristic tilt angles

Abstract

ThCr$_2$Si$_2$-type intermetallics are layered conductors in which crystallographic anisotropy and multiband electronic states often give rise to characteristic magnetotransport phenomena. Here, we report the molecular-beam epitaxy growth of LaAg$_2$Ge$_2$ thin films on MgO(001) and their magnetotransport properties. The Hall effect and magnetoresistance are captured by an effective two-carrier description with a high-mobility electron band, yielding a positive magnetoresistance of 22.5% at 9 T. Angle-dependent magnetoresistance exhibits a dominant twofold anisotropy and additional reproducible dip/peak features at characteristic tilt angles that are nearly independent of field and temperature. These results extend our understanding of the anisotropic electronic transport in thin-film germanides within the ThCr$_2$Si$_2$ family.