Determination of magnetic-moment direction using x-ray resonant exchange scattering

C. Detlefs, A. H. M. Z. Islam, A. I. Goldman, C. Stassis, and P. C. Canfield

Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011.

J. P. Hill and D. Gibbs

Department of Physics, Brookhaven National Laboratory, Upton, New York 11973

(Received 7 October 1996)

We present determination of the magnetic structure of NdNi2B2C and SmNi2B2C by means of x-ray resonant exchange scattering (XRES). The integrated intensity of a number of magnetic reflections was measured as a function of the Bragg angle and compared to model calculations for various magnetic structures. The two compounds were found to have the same magnetic modulation wave vector but different moment directions. A resonant feature observed below the Sm L3-absorption edge, similar to unexplained effects found in other light rare-earth compounds, is identified as quadrupolar XRES and is used to refine the details of the moment direction.

Phys. Rev. B 55, R680 (1996).