Neutron powder diffraction study ( T = 4.2-300 K) and polarization analysis of YBaCuFeO5+δ

Abstract

Abstract The crystal and magnetic structures of the perovskite YBaCuFeO5+δ have been studied in the temperature range T = 4.2-300 K by powder neutron diffraction. In addition to the antiferromagnetic ordering transition at TN  = 442 K, a commensurate–incommensurate magnetic transition is detected at TN ′ = 190 K. Below this temperature, two sets of satellite peaks surround the (1/2,1/2,1/2) magnetic peak at d ∼ Å, collapsing into a single set of satellites below 155 K. Polarization analysis has been performed to confirm the magnetic nature of the (1/2,1/2,1/2)± satellites.