Lattice Distortion to Stabilize the Spin-Peierls State in CeRu2Al10

Abstract

We propose a relevant lattice distortion to stabilize the spin-Peierls state in CeRu2Al10, compatible with the 27Al-NQR spectra and the neutron diffraction patterns on the assumption that Al atoms at Al(1) to Al(4) sites displace toward their respective neighboring Ce ions below T0 = 27 K, leaving Ce, Ru, and Al at Al(5) immobile. Due to a resulting regular lattice distortion the assembly of one-dimensional spin-Peierls order on each zigzag chain along the c-axis predicted by the author becomes a three-dimensional order with Q = (0, 0, 1), where bonds connecting dimerized pair of Ce ions form an antiferro ordering in a body-centered structure.