Microstructure and electrical properties of new high-entropy rare-earth zirconates

In the present work, a series of new high-entropy rare-earth zirconates were prepared by a solid state reaction method. The crystal structure, microstructure and electrical properties of high-entropy rare-earth zirconates were characterized by means of X-ray diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy and electrochemical impedance spectroscopy. All the high-entropy rare-earth zirconates have a single-phase pyrochlore structure with a relative density of more than 95.7%. The grain sizes of high-entropy rare-earth zirconates are 1.3–2.4 µm, which are finer than low-entropy rare-earth zirconates prepared by the same process. (Nd_0.2Sm_0.2Eu_0.2Gd_0.2Dy_0.2)₂Zr₂O₇ has the excellent electrical conductivity of 7.1 × 10^–3 S·cm^–1 at 1073 K.