Abstract
Neutron-scattering experiments have been performed on (Formula presented) that consists of both chains and ladders of copper ions. We observed that the magnetic excitations from the (Formula presented) chain have two branches and that both branches are weakly dispersive along the a and c axes. The (Formula presented) dispersion relation as well as the intensities can be reasonably described by a random-phase approximation with intradimer coupling (Formula presented) interdimer coupling along the c axis (Formula presented) and interdimer coupling along the a axis (Formula presented) The dimer configuration indicates a quasi-two-dimensional hole ordering, resulting in an ordering of magnetic (Formula presented) with spin-(Formula presented) and nonmagnetic Cu, which forms the Zhang-Rice singlet. We have also studied the effect of Ca substitution for Sr on the dimer and the hole ordering.
Original language | English |
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Pages (from-to) | 1060-1067 |
Number of pages | 8 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 59 |
Issue number | 2 |
DOIs | |
State | Published - 1999 |
Externally published | Yes |