Tetragonal and Orthorhombic Phases in Polycrystalline Sr₄Ir₃O₁₀ Synthesized by High-Pressure and High-Temperature Technique

The macroscopic physical properties of materials are determined by their crystal and electronic structures. Iridates have anomalous electronic structures because of the competition of comparable energies between the Coulomb repulsion of electrons and spin-orbit coupling. The polycrystalline Sr4Ir3O10 sample is successfully synthesized, which owns a trilayered perovskite structure using the high-pressure and high-temperature technique. The transmission electron microscopy studies give the structural evidence of Sr4Ir3O10 in real space experimentally. It is proved that tetragonal and orthorhombic structures with I4/mmm and Pbca space groups coexist in the polycrystalline Sr4Ir3O10 sample.