The synthesis of high-entropy perovskite oxide epitaxial thin films using a pulsed laser deposition technique

摘要

ABO_3 perovskite oxides exhibit excellent and diverse physical properties for applications in a variety of areas, such as solid oxide fuel cells, proton conductors, photocatalysts, dielectrics, ferroelectrics, and multiferroics. Recently, ABO_3 perovskite has been extended to high-entropy compositions to explore an unexpected functionality . In general, a single structural phase of high-entropy perovskite oxides (HEPOs) is formed by enhancing the configurational entropy of a multiple component solid solution through mixing a large number of cations. However, the synthesis of HEPOs is at a very early stage, and thus, the stabilization of the perovskite structure has yet to be well studied . Accordingly, we focused on the synthesis of HEPO epitaxial thin films, containing a variety of cations in A and B sites with more than 10 elements. As a result, we succeeded in the synthesis of a single phase of HEPO epitaxial thin films, which contains Ca, Sr, and Ba in A site and Si, Ti, Cr, Mn, Fe, Co, Ni, Ge, Zr, Sn, Ce, and Hf in B site in equiatomic ratios, respectively (Figure 1(a)).