Ce multipoles in phase IV of Ce{sub 0.7}La{sub 0.3}B{sub 6} inferred from resonant x-ray Bragg diffraction

Journal Article · Thu Feb 01 04:00:00 EST 2007 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.75.054401· OSTI ID:20976673

Lovesey, S W; Fernandez-Rodriguez, J; Blanco, J A; Tanaka, Y ^[1]

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1. ISIS Facility, Rutherford Appleton Laboratory, Oxfordshire OX11 0QX (United Kingdom) and RIKEN SPring-8 Center, Harima Institute, Sayo, Hyogo 679-5148 (Japan)

Low temperature properties of Ce{sub 0.7}La{sub 0.3}B{sub 6} in zero external magnetic field in a small temperature range, below 1.4 K, point to the existence of a phase IV characterized by a nonconventional electron ground state with no ordering of 4f magnetic dipole Ce moments. We report a successful analysis of extensive observations on phase IV made by resonant x-ray Bragg diffraction at the Ce L{sub 2} absorption edge. In the analysis, we explore contributions to diffraction by the four domains arranged with triad axes placed along [111], [111], [111], and [111] and from all possible Ce multipoles up to hexadecapoles. Ce quadrupoles and octupoles adequately represent intensity observed in the azimuthal-angle scans for both rotated and unrotated polarization channels at the Bragg reflection ((3/2)(3/2)(3/2)) measured by Mannix et al. [Phys. Rev. Lett. 95, 117206 (2005)]. In this scenario, the magnetic properties of the alloy are due to an antiferromotif of octupoles. While the antiferroquadrupole contribution calculated for ((3/2)(3/2)(3/2)) has a small influence in the azimuthal-angle dependence we predict that for the reflection ((1/2)(1/2)(1/2)) this contribution would radically influence the azimuthal dependence of the intensity. We demonstrate that available data are adequately described also by one microdomain with antiferro-ordering of Ce octupoles and hexadecapoles. In this case, octupole ordering signifies the departure from a cubic chemical structure.

• OSTI ID: 20976673
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 5 Vol. 75; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
ANTIFERROMAGNETIC MATERIALS
BORON ALLOYS
BRAGG REFLECTION
CERIUM ALLOYS
ELECTRONS
GROUND STATES
HEXADECAPOLES
LANTHANUM ALLOYS
MAGNETIC DIPOLES
MAGNETIC FIELDS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
OCTUPOLES
QUADRUPOLES
TEMPERATURE RANGE 0065-0273 K
X RADIATION
X-RAY DIFFRACTION