Neutron diffraction investigation of the crystal and magnetic structures in KCrF3 perovskite

TitleNeutron diffraction investigation of the crystal and magnetic structures in KCrF3 perovskite
Publication TypeJournal Article
Year of Publication2010
AuthorsXiao Y, Su Y, Li HF, Kumar CMN, Mittal R, Persson J, Senyshyn A, Gross K, Brueckel T
Journal TitlePhysical Review B
Volume82
Pages094437
Date Published09/23
ISBN Number1098-0121
Accession NumberISI:000282097200002
Keywordsdistortion, INSULATOR, LAMNO3, physics, superexchange, TRANSITIONS, weak ferromagnetism
Abstract

KCrF3 represents another prototypical orbital-ordered perovskite, where Cr2+ possesses the same electronic configuration of 3d(4) as that of strongly Jahn-Teller distorted Mn3+ in many colossal magnetoresistance manganites. The crystal and magnetic structures of KCrF3 compound are investigated by using polarized and unpolarized neutron powder-diffraction methods. The results show that the KCrF3 compound crystallizes in tetragonal structure at room temperature and undergoes a monoclinic distortion with the decrease in temperature. The distortion of the crystal structure indicates the presence of cooperative Jahn-Teller distortion which is driven by orbital ordering. With decreasing temperature, four magnetic phase transitions are observed at 79.5, 45.8, 9.5, and 3.2 K, which suggests a rich magnetic phase diagram. Below T-N = 79.5 K, the Cr2+ moment orders in an incommensurate antiferromagnetic arrangement, which can be defined by the magnetic propagation vector (1/2 + delta, 1/2 + delta, 0). The incommensurate-commensurate magnetic transition occurs at 45.8 K and the magnetic propagation vector locks into (1/2, 1/2, 0) with the Cr moment of 3.34(5) mu(B), aligned ferromagnetically in (220) plane, but antiferromagnetically along [110] direction. Below 9.5 K, the canted antiferromagnetic ordering and weak ferromagnetism arise from the collinear antiferromagnetic structure while the Dzyaloshinskii-Moriya interaction and tilted character of the single-ion anisotropy might give rise to the complex magnetic behaviors below 9.5 K.

URL<Go to ISI>://000282097200002http://prb.aps.org/pdf/PRB/v82/i9/e094437
DOI10.1103/Physrevb.82.094437
Alternate JournalPhys Rev B