A new chiral phase of BiFeO3 evidenced from resonant x-ray Bragg diffraction

DOI: 10.1088/1742-6596/519/1/012012

Authors: Angel Rodriguez-fernandez (University of Oviedo) , Stephen Lovesey (Diamond Light Source) , Steve Collins (Diamond Light Source) , Gareth Nisbet (Diamond Light Source) , J A Blanco Rodriguez (Universidad de Oviedo)
Co-authored by industrial partner: No

Type: Conference Paper
Conference: REXS 2013 — Workshop on Resonant Elastic X-ray Scattering in Condensed Matter
Peer Reviewed: Yes

State: Published (Approved)
Published: May 2014
Diamond Proposal Number(s): 7720

Abstract: Results that support a new chiral phase in the only multiferroic material known above room temperature have been obtained by a resonant x-ray Bragg diffraction experiment, with the incoming x-ray beam tuned near the Fe K-edge (7.1135 keV), performed in its ferroelectric phase. The R3c forbidden reflection (0,0,9)H was studied as a function of the rotation of the crystal about the Bragg wavector in both phases, paramagnetic (700 K) and antiferromagnetic (300 K). The data gathered is consistent with a chiral structure formed by a circular cycloid propagating along (1,1,0)H. Templeton and Templeton (T&T) scattering at 700 K is attributed in part to charge-like quadrupoles absent in a standard model of a cycloid in which a material vector generates all electronic states of the resonant ion. Extensive sets of azimuthal-angle data are used to infer values of three atomic multipoles in a satisfactory minimal model of the iron electronic structure, with a quadrupole (E1-E1 event) and a hexadecapole (E2-E2 event) contributing T&T scattering, plus a magnetic dipole (E1-E1).

Journal Keywords: Antiferromagnetism; Bismuth Compounds; Bragg Reflection; Chirality; Crystals; Electronic Structure; Ferrites; Ferroelectric Materials; Indium Fluorides; Iron; Magnetic Dipoles; Paramagnetism; Quadrupoles; Temperature Dependence; Trigonal Lattices

Subject Areas: Materials


Instruments: I16-Materials and Magnetism

Added On: 23/03/2015 15:51

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