Electronic and magnetic properties of La4Ni3-xCuxO8 and Nd4-ySmyNi3O8

To tune the electronic state of novel layered nickelate La4Ni3O8 and subsequently to derive superconductivity, we have doped with Cu for the Ni in La4Ni3O8, replaced La with Nd in La4Ni3O8, and doped with Sm for the Nd in Nd4Ni3O8, and investigated the electronic and magnetic properties of the resulting La4Ni3 xCuxO8 and Nd4 ySmyNi3O8. For the La4Ni3 xCuxO8 system, the a(c)-axis length increased (decreased) with increase in Cu-doping, accompanied by an increase in electrical resistivity. For the Nd4 ySmyNi3O8 system, by shrinkage of the lattice through replacement of the La by Nd, and Sm-doping of Nd4Ni3O8, we succeeded in reducing the electrical resistivity. We conclude that the shrinkage of especially the a-axis length induced by chemical pressure is effective in reducing the electrical resistivity of this system and by applying physical pressure it is strongly hoped that superconductivity will be obtained in Nd4 ySmyNi3O8. (C) 2013 Elsevier B.V. All rights reserved.