Enhancement of Charge Order by Heteroepitaxial Strain in Manganite/Cuprate Multilayers

We examine the role that epitaxial strain plays on the enhancement of the CuO­₂ charge order that was observed in superlattices of YBa₂Cu₃O_7-δ (YBCO) and La_2/3Ca_1/3MnO₃ (LCMO) [1]. Resonant x-ray scattering was used to measure the charge order onset temperature (T_CO) in c-axis LCMO/YBCO/LCMO thin films at different YBCO thicknesses and oxygen contents. These trilayers were grown using pulsed laser-ablated deposition and characterized using x-ray diffraction and reflectometry, electrical transport, and x-ray absorption spectroscopy. We find higher T_CO in trilayers with thinner YBCO layers even after accounting for strain-induced changes to its oxygen content . Our results indicate that the charge order in LCMO/YBCO multilayers can be enhanced by the epitaxial strain inherent in such heterostructures.

[1] Frano et. al. Nat. Mat 15 (2016)