2005/09/21 by X. G. Luo, X. Li, Xin Li +6
Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Catalysis #Chemistry #Cobalt #Condensed matter physics #Crystallography #Doping #Ferromagnetism #Inorganic chemistry #Magnetic and transport properties of perovskites and related materials #Materials science #Multiferroics and related materials #Physics #Spin (aerodynamics) #Spin states #Thermodynamics #Transition metal #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1016/j.jssc.2006.04.011
11 figures
arxiv created 2005/09/21 · openalex publication_date 2006/06/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Resistivity and dc magnetization measurements were performed for the polycrystalline Pr0.5Ca0.5Co1-xFexO3-δ (x = 0, 0.05, 0.10 and 0.15) samples. The as-fabricated samples exhibit ferromagnetic (FM) transition and the transition temperature increases with increasing the iron doping level. Annealing under high oxygen pressure induces a spin-state transition of Co ions in the iron-free sample and such transition is reinforced with increasing the annealing oxygen pressure, while the annealing under high oxygen pressure suppresses the ferromagnetic ordering. Contrary to the case of the iron-free sample, no spin-state transition is induced by the annealing under high oxygen pressure for the iron-doped samples, and the ferromagnetic transition temperature is nearly independent of the annealing procedures. The enhancement of the spin-state transition in the iron-free sample after annealing under high oxygen pressure should be attributed to the reduction of the cell volume. The suppression of the spin-state transition by the Fe doping is related to the enlargement of the cell volume and the stronger Fe-O bonds than Co-O bonds. The enhancement of the ferromagnetism by the iron-doping might arise from the ferromagnetic exchange interaction between Fe3+ and Co4+ through oxygen (Fe3+-O-Co4+).