We report on the epitaxial growth and surface structure of infinite-layer cuprate Sr1-xNdxCuO2 films on SrTiO3(001) substrates by combining ozone-assisted molecular beam epitaxy and in situ scanning tunneling microscopy. Careful substrate temperature and flux control has been used to achieve single-phase, stoichiometric, and c-axis oriented films. The surface of the films is usually characterized by a mixed CuO2 surface and gridlike superstructure. The superstructure exhibits a periodicity of 3.47 nm that corresponds to a coincidence lattice between the overlayer peroxide SrO2 and underlying CuO2 plane, and gives rise to a conductance spectrum that is distinct from the Mott-Hubbard band structure of CuO2. At a higher Nd composition x > 0.1, a (2 x 2) surface characteristic of the hole-doped CuO2 emerges, which we ascribe to the intake of apical oxygens in the intervening Sr planes.
@article{arxiv.2008.05725,
title = {Molecular beam epitaxy growth and surface structure of Sr1-xNdxCuO2 cuprate films},
author = {Jia-Qi Fan and Shu-Ze Wang and Xue-Qing Yu and Rui-Feng Wang and Yan-Ling Xiong and Can-Li Song and Xu-Cun Ma and Qi-Kun Xue},
journal= {arXiv preprint arXiv:2008.05725},
year = {2020}
}