2004/08/04 by X. G. Luo, X. H. Chen, X. Liu +10
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.70.054520
published as Phys. Rev. B 70, 054520 (2004)
arxiv created 2004/08/04 · openalex publication_date 2004/08/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Magnetic and transport properties of CoSr2Y_1\ensuremath-xCaxCu2O7 (x=0--0.4) system have been investigated. A broad maximum in the M(T) curve, indicative of low-dimensional antiferromagnetic ordering originated from CoO_1+\ensuremathδ layers, is observed in the Ca-free sample. With increasing as Ca doping level up to 0.2, the M(T) curve remains almost unchanged, while resistivity is reduced by three orders. A higher Ca doping level leads to a drastic change of magnetic properties. In comparison with the samples with x=0.0--0.2, the temperature corresponding to the maximum of M(T) is much lower for the sample x=0.3. The sample x=0.4 shows a small kink instead of a broad maximum and a weak ferromagnetic feature. The electrical transport behavior is found to be closely related to magnetic properties for the sample x=0.2, 0.25, 0.3, 0.4. It suggests that CoO_1+\ensuremathδ layers are involved in charge transport, in addition to conducting CuO2 planes to interpret the correlation between magnetism and charge transport. X-ray photoelectron spectroscopy studies give additional evidence of the the transfer of the holes into the CoO_1+\ensuremathδ charge reservoir.