Dimerization of CuGeO3 in the spin-Peierls state

Abstract

The dimerization of the Cu ions in the spin-Peierls state of CuGeO3 below 14 K has been determined by neutron-diffraction measurements. In addition to superlattice reflections with indices h2kl2 (h, k, l, all odd) recently observed in electron and x-ray diffraction studies, we also found peaks for which k=5 = even. Oxygen displacements in the a-b plane of about 0.01 , accompanied by comparable shifts of the Cu ions along the chain direction c, can be related to the dimerized spin state in a natural fashion. © 1994 The American Physical Society.