Correlation between the tolerance factor and phase transition in A4–xBxNi3O10 (A and B=La,Pr,and Nd;x=0,1,2,and 3)

We have synthesized a series of the Ruddlesden-Popper nickelate solid solution A4–xBxNi3O10 (A and B=La,Pr,and Nd;x=0,1,2,and 3) via the citrate precursor method in different reacting atmospheres. Both the electronic-transport and magnetization measurements on these samples show well-defined phase transitions at temperatures between 135 and 165 K. These transition temperatures as well as the room-temperature resistivities strongly correlate with the Goldschmidt tolerance factor t, irrespective of the combination of the magnetic rare-earth ions with nonmagnetic La3+. We conclude that these changes of the electronic properties are mostly a consequence of the distortion of the NiO6 octahedra at the phase transition which is intimately related to the tolerance factor t, but appear to be rather insensitive to the average magnetic moment of the rare-earth ions upon exchanging La by Pr or Nd