Conduction mechanisms of epitaxial EuTiO3 thin films

TL;DR

This study investigates the conduction mechanisms in epitaxial EuTiO3 thin films, revealing temperature- and voltage-dependent behaviors including space-charge-limited current, Schottky emission, and Fowler-Nordheim tunneling, with Eu3+ ions contributing to leakage.

Contribution

It provides a detailed analysis of conduction mechanisms in EuTiO3 thin films across different temperatures and biases, highlighting the role of Eu3+ ions in leakage currents.

Findings

Space-charge-limited current dominates from 50 to 150 K.

Schottky emission occurs at 200-300 K under negative bias.

Fowler-Nordheim tunneling occurs at 200-300 K under positive bias.

Abstract

To investigate leakage current density versus electric field characteristics, epitaxial EuTiO3 thin films were deposited on (001) SrTiO3 substrates by pulsed laser deposition and were post-annealed in a reducing atmosphere. This investigation found that conduction mechanisms are strongly related to temperature and voltage polarity. It was determined that from 50 to 150 K the dominant conduction mechanism was a space-charge-limited current under both negative and positive biases. From 200 to 300 K, the conduction mechanism shows Schottky emission and Fowler-Nordheim tunneling behaviors for the negative and positive biases, respectively. This work demonstrates that Eu3+ is one source of leakage current in EuTiO3 thin films.