Isostructural transition coupled with spin ordering in CsCuCl3: A spatially frustrated spiral crystal lattice


Isostructural transition coupled with spin ordering in CsCuCl3: A spatially frustrated spiral crystal lattice

Plakhty, V. P.; Wosnitza, J.; Martin, N.; Marchi, Y.; Smirnov, O. P.; Grenier, B.; Gavrilov, S. V.

By means of single-crystal neutron diffraction, an isostructural transition is observed at the Néel temperature of CsCuCl3, a quasi-one-dimensional antiferromagnet with a helically modulated crystal structure that is built out of six Cu2+ layers. Abrupt atomic displacements of about 0.01 A minimize the ferromagnetic interlayer superexchange interaction via the path Cu-Cl1-Cu that enters also the antiferromagnetic path Cu-Cl1-Cl2-Cu. The latter couples only one pair of Cu2+ ions in each chlorine layer since all the other intralayer bonds either have much longer interatomic distances or include more than two intermediate Cl ions and, therefore, can be neglected. Thus, a spatial geometric frustration in this helically modulated stacked triangular lattice is provided by three Cu layers. Influences of the atomic displacements on the exchange energy, as well as the critical behavior of this spatially frustrated material, are discussed.

  • Physical Review B 79(2009), 012410

Permalink: https://www.hzdr.de/publications/Publ-12666
Publ.-Id: 12666