paper

Epitaxial growth and scanning tunneling microscopy of LiV $_{2}$ O $_{4}$ thin films on SrTiO $_{3}$ (111)

arXiv:2302.10852 · doi:10.1063/5.0140576

Abstract

LiV $_{2}$ O $_{4}$ is a mixed-valent spinel oxide and one of a few transition-metal compounds to host a heavy fermion phase at low temperatures. While numerous experimental studies have attempted to elucidate how its 3 $d$ electrons undergo giant mass renormalization, spectroscopic probes that may provide crucial hints, such as scanning tunneling microscopy (STM), remain to be applied. A prerequisite is atomically flat and pristine surfaces, which, in the case of LiV $_{2}$ O $_{4}$ , are difficult to obtain by cleavage of small, three-dimensional crystals. We report the epitaxial growth of LiV $_{2}$ O $_{4}$ thin films with bulklike properties on SrTiO $_{3}$ (111) via pulsed laser deposition and stable STM imaging of the LiV $_{2}$ O $_{4}$ (111) surface. The as-grown films were transferred $e x$ $s i t u$ to a room-temperature STM, where subsequent annealing with optional sputtering in ultrahigh vacuum enabled compact islands with smooth surfaces and a hexagonal 1 $\times$ 1 atomic lattice to be resolved. Our STM measurements provide insights into growth mechanisms of LiV $_{2}$ O $_{4}$ on SrTiO $_{3}$ (111), as well as demonstrate the feasibility of performing surface-sensitive measurements of this heavy fermion compound.

6 pages, 4 figures + SM

Epitaxial growth and scanning tunneling microscopy of LiV2​O4​ thin films on SrTiO3​(111)

Abstract

Epitaxial growth and scanning tunneling microscopy of LiV $_{2}$ O $_{4}$ thin films on SrTiO $_{3}$ (111)