Structure and electric transport properties of the spin ladder compound Sr14 (Cu0.97 M0.03)24 O41 (M = Zn, Ni, Co)

Polycrystalline samples of Sr14Cu24O41 and Sr-14 (Cu-0.97 M-0.03)(24) O-41 (M = Zn, Ni, Co) were synthesized by standard solid state reaction method. All samples are single phase as identified by X-ray diffraction, no regular shift of lattice parameters a, c is found, but the lattice parameter b increases slightly with doping magnetic ions Ni and Co, and has no change with doping non-magnetic ion Zn, respectively. Selected area electron diffraction experiments show that Zn,Ni and Co ions may substitute for Cu ions in the chain. All the doping compounds are still semiconductors and have a crossover temperature T-p like the parent phase Sr14Cu24O41. The influence of magnetic ion Ni or Co doping on the resistivity is smaller than that of non-magnetic ion Zn doping, while the influence of non-magnetic ion Zn doping on crossover temperature is smaller than that of magnetic ion Ni or Co doping.