The influence of fluorination on thermal conductivity, specific heat, magnetic susceptibility, electrical resistivity and thermoelectric power of La 1.85-ySr 0.15Nd yCuO 4 has been investigated. The temperature variation of the thermal conductivity of the untreated samples with Nd exhibits a change in slope just below the low-temperature structural transition (LTO rarr LTT), which could be associated with strong phonon-electron interaction. The specific heat of the y=0.2 unfluorinated sample presents a jump near 50 K confirming the structural transition. Below 10 K, the specific heat of the two y=0.8 samples (unfluorinated or fluorinated) shows an important increase with decreasing temperature, presumably associated with some type of magnetic ordering in the Nd 3+ ions. In addition to an increase of T c, the fluorination process suppresses the anomalies observed in the thermal conductivity.
Cassart, M. ; Grivei, E. ; Issi, J.-P. ; Hejtmanek, J. ; Robin-Brisson, C. ; et. al. Influence of fluorination on the transport properties of La 1.85-ySr 0.15Nd yCuO 4 near the low-temperature structural transition.1992 European Materials Research Society (E-MRS) Fall Meeting Symposium A: High Temperature Superconductors (Strasbourg, France, 3-6 November 1992). In: Journal of Alloys and Compounds, 1993, p.Vol. 195, p. 335-338
