Structure and cryogenic magnetic properties in Ho2BaCuO5 cuprate.

Here we report on a detailed investigation of the crystal structure, cryogenic magnetic and magneto-caloric properties in Ho 2 BaCuO 5 cuprate. The Ho 2 BaCuO 5 crystallized in the orthorhombic crystal structure with Pbnm space group and undergoes a paramagnetic (PM) to antiferromagnetic (AFM) transition at the Néel temperature ( T N ) of 12.5 K. An obvious signal change in the magneto-caloric effect (MCE) was observed, which is correlated with the fact of the AFM ground state inducing a small negative magnetic entropy change (-Δ S M ) at/below T N and a field-induced metamagnetic transition (first ordered) from AFM to ferromagnetic (FM) producing a large positive -Δ S M above T N . For a magnetic field change of 0–7 T, the -Δ S M max ≈ 10.4 J/kg K, RCP ≈ 263 J/kg and RC ≈ 199 J/kg for the maximum magnetic entropy change, relative cooling power and refrigerant capacity are evaluated, respectively. [ABSTRACT FROM AUTHOR]