Abstract
We report on electron paramagnetic resonance (EPR) measurements on the S=12 quasi-one-dimensional system (Sr,Ca)10Cu17O29, doped with Y, Bi, Pb and Al, which has simple chains and two-leg ladder chains of copper ions. A very broad absorption line, coming from the ladder chains, dominates near room temperature. The EPR signals observed below room temperature mainly come from the simple (dimerized) chains. A detailed analysis of the temperature dependencies of the resonance field, line width and intensity of EPR signal is presented. EPR spectra of Cu2+ ions located in chains are described in terms of Wannier excitons. It is also found that at low temperatures the EPR line experiences a sharp broadening and shifts to the lower field region. These findings are discussed by taking into account two different mechanisms: the magnetic dipole interactions among short-range ordered Cu2+ spins in the chains and the exchange interaction between Cu2+ ions located in chains and holes (“bottleneck effect”).
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
