High-pressure synthesis and magnetic properties of tetragonal R₂BaCuO₅ (R = Sm and Eu).

ABSTRACT: We report the experimental discovery of a new structural phase of well-known orthorhombic R ₂BaCuO₅ (R = Sm and Eu), exhibiting a tetragonal crystal structure with space group P4∕mbm. The high-pressure tetragonal phase is isostructural with the brown phase R ₂BaCuO₅ (R = La, Pr, and Nd). In this structure, the Cu ions form an isolated square planar environment, contrary to the orthorhombic phase, where the Cu ions are located in a distorted square pyramid. Magnetization and specific heat measurements reveal the long-range antiferromagnetic order of the Cu²⁺ and/or Sm³⁺ moments for the Sm-sample, with the magnetic specific heat accounting for only 35% of the magnetic entropy. Interestingly, the Eu-

SUBMITTER: Mishra S 

PROVIDER: S-EPMC10288855 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature