Neutron-scattering experiments were performed on the undoped and hole-doped Ca 2+xY 2-xCu 5O 10, which consists of ferromagnetic edge-sharing CuO 2 chains. It was previously reported that in the undoped Ca 2Y 2Cu 5O 10 there is an anomalous broadening of spin-wave excitations along the chain, which is caused mainly by the antiferromagnetic interchain interactions [M. Matsuda et al., Phys. Rev. B 63, 180403(R) (2001)]. A systematic study of temperature and hole concentration dependencies of the magnetic excitations shows that the magnetic excitations are softened and broadened with increasing temperature or doping holes irrespective of Q direction. The broadening is larger at higher Q. A characteristic feature is that hole doping is much more effective to broaden the excitations along the chain. It is also suggested that the intrachain interaction does not change so much with increasing temperature or doping although the anisotropic interaction and the interchain interaction are reduced. In the spin-glass phase (x=1.5) and nearly disordered phase (x =1.67) the magnetic excitations are much broadened in energy and Q. It is suggested that the spin-glass phase originates from the antiferromagnetic clusters, which are caused by the hole disproportionation.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2005 Mar 1|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics