Synthesis and characterization of dense Gd2Ti2O7 pyrochlore thin films deposited using RF magnetron sputtering

TL;DR

This study successfully synthesized dense, phase-pure Gd2Ti2O7 pyrochlore thin films using RF magnetron sputtering, confirming their structure and measuring their electrical properties, with notable differences from bulk material.

Contribution

First demonstration of dense Gd2Ti2O7 pyrochlore thin films via RF magnetron sputtering with detailed structural and electrical characterization.

Findings

Films are dense and uniform with ~8nm surface roughness.

Electrical conductivity similar to bulk Gd2Ti2O7.

Differences in Arrhenius behavior due to impurities.

Abstract

Thin films of phase pure pyrochlore Gd2Ti2O7 have been synthesized by RF magnetron sputtering. The films were prepared from oxide targets in 50%O2/Ar atmosphere and deposited on 111 YSZ substrates at a temperature of 800C. The pyrochlore structure was confirmed via grazing angle x-ray diffraction and selected area electron diffraction (SAED). TEM analysis also showed that the films were dense and of uniform thickness with surface roughness of approximately 8nm. The total conductivity measured with AC impedance spectroscopy was found to be independent of thickness and comparable in magnitude to that of bulk Gd2Ti2O7. Differences were observed in the Arrhenius behavior between the bulk and thin film samples and are attributed to varying levels of background impurities.