Magnetoelastic tetragonal-to-orthorhombic distrotion in ErNi2B2C

C. Detlefs, A. H. M. Z. Islam, T. Gu, 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 T. Vogt

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

(Received 10 March 1997)

We have performed synchrotron x-ray scattering experiments on single crystals of ErNi2B2C. Below 6.3 K, the (2,0,0) Bragg peak splits, indicating a tetragonal-to-orthorhombic distortion. The mismatch between the a and b lattice parameters appears coincident with the onset of long-range antiferromagnetic order and increases continuously with decreasing temperature, reaching a value of a/b - 1 ~ 0.2% at 3.7 K.

Phys. Rev. B 56, 7843 (1997).