Broken chain effect in doped SrCuO2

We report the effect of magnetic (Ni) and nonmagnetic (Zn, Ga) doping on the overall magnetic behaviour of the spin chain compound SrCuO(2). The doping causes systematic reduction in the intrachain exchange interaction, and the influence is found to be almost independent of the dopant. The low temperature Curie tail in the temperature dependence of susceptibility also increases with the doping concentration, which is an indication of the enhanced chain breaking effect with doping. The doping also gives rise to nonlinearity in the isothermal magnetization behaviour, which can be accounted for by the effect of free/quasi-free spin in the doped sample. Our analysis indicates that doped Ni(2+) ions remain in a low spin state (S = 0) and behave almost similar to the nonmagnetic counterpart as far as the doping effects are concerned.