A procedure for the preparation of the starting oxides has allowed phase-pure synthesis of the rhombohedral, metallic perovskite system ${\mathrm{La}}_{1-x}{\mathrm{Nd}}_x{\mathrm{CuO}}_3$ $(0\mathrm{}<~x<~0.6)$ under 25 kbar oxygen pressure at $900–1000°\mathrm{C}.$ It was not possible to exceed the $x=0.6\mathrm{}$ limit with 65 kbar at $1600°\mathrm{C}.$ Measurement of the ${\mathrm{CuO}}_3$-sublattice contribution to the paramagnetic susceptibility ${\chi }_m\mathrm{}\left(T\right)\mathrm{}$ was obtained for samples of different x by an appropriate subtraction of the ${\mathrm{Nd}}^{3+}$-ion contribution as obtained from measurement of ${\chi }_m\mathrm{}\left(T\right)\mathrm{}$ for ${\mathrm{NdAlO}}_3.$ The data are qualitatively compatible with the Mott prediction for a mass-enhanced ${\chi }_m\mathrm{}\left(T\right)\mathrm{}$ of a half-filled band that approaches the Mott-Hubbard transition from the itinerant-electron side. However, a model of strong-correlation fluctuations in a mass-enhanced Fermi liquid provides an alternative description of the data that is supported by transport measurements and a remarkable sensitivity of the susceptibility to small structural changes.

• Received 19 August 1999

DOI:https://doi.org/10.1103/PhysRevB.61.3196