Metallic ferromagnetism in Ni-doped La0.7Sr0.3CoO3

The structure, magnetization, and electrical transport of perovskite cobaltites La0.7Sr0.3Co1-yNiyO3 have been studied. It is found that the substitution of Ni for Co induces no apparent changes in bond length and angle in the Co(Ni)-O network, and only moderately suppresses the ferromagnetism. Moreover, a retention of the metallic conduction has been observed from y=0 to 0.2, which is in strong contrast to the reported insulating state of the other Co site doped La0.7Sr0.3CoO3. A double-exchange-like interaction between Ni ion and its neighboring Co ion is suggested to explain the experimental results. (C) 2002 American Institute of Physics.