PdCrO2 films are synthesized on CuCrO2 buffer layers on Al2O3 substrates. This synthesis is accompanied by impurity phase segregation, which hampers the synthesis of high quality PdCrO2 films. The potential causes of impurity phase segregation were studied by using a combination of experiments and ab initio calculations. X-ray diffraction and scanning transmission electron microscopy experiments revealed impurity phases of CuxPd1−x alloy and chromium oxides, Cr2O3 and Cr3O4, in PdCrO2. Calculations determined that oxygen deficiency can cause the impurity phase segregation. Therefore, preventing oxygen release from delafossites could suppress the impurity phase segregation. The amounts of Cr2O3 and Cr3O4 depend differently on temperature and oxygen partial pressure. A reasonable theory-based explanation for this experimental observation is provided.
@article{arxiv.2303.08377,
title = {Control of Impurity Phase Segregation in a PdCrO$_2$/CuCrO$_2$ Heterostructure},
author = {Tom Ichibha and Sangmoon Yoon and Jong Mok Ok and Mina Yoon and Ho Nyung Lee and Fernando A. Reboredo},
journal= {arXiv preprint arXiv:2303.08377},
year = {2023}
}