Suppression of Magnetic Phase Separation in Epitaxial SrCoOx Films

TL;DR

This study demonstrates that epitaxial SrCoOx films prepared with fast quenching suppress magnetic phase separation observed in bulk materials, with film thickness influencing phase coexistence during oxidation and reduction cycles.

Contribution

It reveals that finite thickness effects in epitaxial SrCoOx films prevent magnetic phase separation, unlike bulk samples, highlighting the role of film thickness in phase behavior.

Findings

200nm films remain single phase during oxidation

300nm films show phase coexistence during deoxidation

Finite thickness influences phase separation suppression

Abstract

Using pulsed laser deposition and a unique fast quenching method, we have prepared SrCoOx epitaxial films on SiTiO3 substrates. As electrochemical oxidation increases the oxygen content from x = 2.75 to 3.0, the films tend to favor the discrete magnetic phases seen in bulk samples for the homologous series SrCoO(3-n/8) (n = 0, 1, 2). Unlike bulk samples, 200nm thick films remain single phase throughout the oxidation cycle. 300 nm films can show two simultaneous phases during deoxidation. These results are attributed to finite thickness effects and imply the formation of ordered regions larger than approximately 300 nm.