N. T. Dang, D. P. Kozlenko, S. E. Kichanov, S. G. Jabarov, A. I. Mammadov, R. Z. Mekhtieva, T. L. Phan, V. G. Smotrakov, V. V. Eremkin, B. N. Savenko. Revealing the Formation Mechanism and Effect of Pressure on the Magnetic Order of Multiferroic BiMn2O5 Through Neutron Powder Diffraction. (2017). Journal of Electronic Materials. 46(6), 3373–3380 (ISI, IF = 1.579)

Ngày: 17/10/2017

Abstract

The crystal and magnetic structures of the strong magnetoelectric BiMn2O5 have been studied as a function of pressure up to 5.7 GPa in the temperature range from 10 K to 60 K by means of neutron powder diffraction. The results reveal that the Pbam orthorhombic crystal structure remains unchanged in the investigated thermodynamic range. At ambient pressure, a long-range commensurate antiferromagnetic (AFM) phase with propagation vector q = (1/2, 0, 1/2) formed below TN = 41(2) K, accompanied by anomalies in the temperature dependence of structural parameters including the lattice parameters, interatomic distances, and bond angles. This AFM phase remained stable␣in the studied pressure range, and the relevant pressure coefficient of the Néel temperature was determined to be 3.0(4) K/GPa. No incommensurate AFM phase was detected. The magnetic properties of BiMn2O5 and their difference from most other RMn2O5 compounds were analyzed in terms of competing exchange interactions.