Enhanced metallic properties of SrRuO3 thin films via kinetically controlled pulsed laser epitaxy

TL;DR

This paper demonstrates that by controlling the kinetics during pulsed laser epitaxy, high-quality SrRuO3 thin films with enhanced conductivity and Curie temperature can be achieved, improving their suitability for electronic device applications.

Contribution

It introduces a kinetically controlled pulsed laser epitaxy method with real-time spectroscopic monitoring to produce superior SrRuO3 thin films.

Findings

Enhanced conductivity and T_C in thin films compared to bulk values.

Improved stoichiometry and strain-mediated bandwidth increase.

High-quality films down to 16 nm thickness.

Abstract

Metal electrodes are a universal element of all electronic devices. Conducting SrRuO3 (SRO) epitaxial thin films have been extensively used as electrodes in complex-oxide heterostructures due to good lattice mismatches with perovskite substrates. However, when compared to SRO single crystals, SRO thin films have shown reduced conductivity and Curie temperatures (T_C), which can lead to higher Joule heating and energy loss in the devices. Here, we report that high-quality SRO thin films can be synthesized by controlling the plume dynamics and growth rate of pulsed laser epitaxy (PLE) with real-time optical spectroscopic monitoring. The SRO thin films grown under the kinetically controlled conditions, down to ca. 16 nm in thickness, exhibit both enhanced conductivity and T_C as compared to bulk values, due to their improved stoichiometry and a strain-mediated increase of the bandwidth of Ru 4d electrons. This result provides a direction for enhancing the physical properties of PLE-grown thin films and paves a way for improved device applications.