Local Weak Ferromagnetism in Single-Crystalline Ferroelectric BiFeO3


Ramazanoglu M. K. , Laver M., RATCLIFF W., WATSON S. M. , CHEN W. C. , JACKSON A., ...More

PHYSICAL REVIEW LETTERS, vol.107, no.20, 2011 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 107 Issue: 20
  • Publication Date: 2011
  • Doi Number: 10.1103/physrevlett.107.207206
  • Title of Journal : PHYSICAL REVIEW LETTERS

Abstract

Polarized small-angle neutron scattering studies of single-crystalline multiferroic BiFeO3 reveal a long-wavelength spin density wave generated by similar to 1 degrees spin canting of the spins out of the rotation plane of the antiferromagnetic cycloidal order. This signifies weak ferromagnetism within mesoscopic regions of dimension 0.03 microns along [1 (1) over bar0], to several microns along [111], confirming a long-standing theoretical prediction. The average local magnetization is 0.06 mu(B)/Fe. Our results provide an indication of the intrinsic macroscopic magnetization to be expected in ferroelectric BiFeO3 thin films under strain, where the magnetic cycloid is suppressed.