Approach to Curie-Weiss paramagnetism in the metallic perovskites La1-xNdxCuO3

A procedure for the preparation of the starting oxides has allowed phase-pu re synthesis of the rhombohedral, metallic perovskite system La1-xNdxCuO3 ( 0 less than or equal to x less than or equal to 0.6) under 25 kbar oxygen p ressure at 900-1000 degrees C. It was not possible to exceed the x = 0.6 li mit with 65 kbar at 1600 degrees C. Measurement of the CuO3-sublattice cont ribution to the paramagnetic susceptibility X-m(T) was obtained for samples of different x by an appropriate subtraction of the Nd3+-ion contribution as obtained from measurement of X-m(T) for NdAlO3. The data are qualitative ly compatible with the Mott prediction for a mass-enhanced X-m(T) 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 ma ss-enhanced Fermi liquid provides an alternative description of the data th at is supported by transport measurements and a remarkable sensitivity of t he susceptibility to small structural changes.