Electron spin resonance study of the dynamic magnetic susceptibility of CuO, Cu1-xZnxO, and Cu1-xLixO single crystals

Results are presented of studies of the dynamic magnetic susceptibility of CuO, Cu1- xZnxO (x approximate to 1.5%), and Cu1- xLixO (x approximate to 1 %) single crystals. The orientational dependence of the ESR spectra was inv estigated at room temperature. The results for CuO are analyzed using a mod el of a quasi-one-dimensional antiferromagnet (S = 1/2) with anisotropic ex change interaction between Cu2+ spins in the chains and exchange coupling b etween the chains allowing for one-dimensional spin diffusion and spinon ex citations. The estimated line width is of the same order of magnitude as th e experimental data. Substituting Cu with Zn scarcely alters the spin dynam ics of the Cu2+ ions, as in weakly diluted magnets. Lithium doping substant ially increases the ESR line width and this is attributed to excess holes f orming rapidly relaxing spin complexes with copper ions. (C) 2000 MAIK "Nau ka/Interperiodica".