  We have synthesized a series of the Ruddlesden-Popper nickelate solid
solution Ln4-xLn'xNi3O10 (Ln and Ln' = La, Pr and Nd; x = 0, 1, 2 and 3) via
the citrate precursor method at different reacting atmospheres. Both the
electronic-transport and magnetization measurements on these samples show
well-defined phase transitions at temperatures between 135 K and 165 K. These
transition temperatures, the room-temperature resistivities, as well as the
changes of the Pauli-paramagnetic susceptibilities at the respective phase
transitions, strongly correlate with the Goldschmidt tolerance factor t,
irrespective of the combination of the magnetic rare-earth ions with unmagnetic
La3+. We conclude that these changes of the electronic properties are mostly
related to the distortion of the NiO6 octahedra at the phase transition which
is strongly correlated with the tolerance factor t, but are rather insensitive
to the magnetism of the rare-earth ions Ln3+ and Ln'3+.
