A stable and reproducible superconductivity transition between 80 and 93 K has been unambiguously observed both resistively and magnetically in a new Y-Ba-Cu-0 compound system at ambient pressure. An estimated upper critical field H, 2(0) between 80 and 180 T was obtained.

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The Raman and infrared phonons of isostructural rhombohedral LaMnO 3 and LaAlO 3 are studied at room temperature. The experimental spectra are compared with the prediction of lattice-dynamical calculations and the lines observed are assigned to definite atomic vibrations. It is shown that the Raman mode of A 1g symmetry in LaAlO 3 and LaMnO 3 ͑at 123 cm Ϫ1 and 236 cm Ϫ1 , respectively͒ involves atomic motions that cause the rhombohedral distortion, i.e., it is a ''soft'' mode, and its position could be used as a measure of the degree of the distortion. It is also argued that the broad Raman bands in the high-frequency range of LaMnO 3 are not proper modes of the rhombohedral R3 c structure, but are rather induced by the dynamic Jahn-Teller effect.

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An apparent superconducting transition with an onset temperature above 40 K has been detected under pressure in the La-Ba-Cu-0 compound system synthesized directly from a solid-state reaction of La203, CuO, and BaCO3 followed by a decomposition of the mixture in a reduced atmosphere. The experiment is described and the results of effects of magnetic field and pressure are discussed.

We report a careful 59Co nuclear quadrupolar resonance measurement on the recently discovered cobalt oxyhydrate Na0.35CoO2.yH(2)O superconductor from T=40 K down to 0.2 K. We find that in the normal state the spin-lattice relaxation rate 1/T(1) follows a Curie-Weiss type temperature (T) variation, 1/T(1)T=C/(T-theta), with theta=-42 K, suggesting two-dimensional antiferromagnetic spin correlations. Below T(c)=3.9 K, 1/T(1) decreases with no coherence peak and follows a T(n) dependence with n approximately 2.2 down to approximately 2.0 K but crosses over to a 1/T(1) proportional to T variation below T=1.4 K, which suggests non-s-wave superconductivity. The data in the superconducting state are most consistent with the existence of line nodes in the gap function.

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