Hall effect in NdL85Ceo.xsCuOy with controlled oxygen content

J.I. MARTIN; A. SERQUIS; F. PRADO; D. JAQUE; A. CANEIRO; J. L. VICENT

PHYSICA C - SUPERCONDUTIVITY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2000 vol. 341 p. 1943 - 1944

0921-4534

NdL85Ce0.15CUl.01Oy ceramic samples with accurate control of the oxygen content have been prepared tostudy their electronic properties in comparison with their superconducting behavior. The oxygen content hasbeen varied in the range 3.995 < y < 4.007 by annealing under controlled oxygen partial pressure and subsequentquenching. The samples change from superconducting for the lowest oxygen content (Tc = 20 K) to nonsuperconductingfor the highest y value. The normal state Hall effect presents a negative RH coefficient in all thesuperconducting samples. The Hall effect shows an almost temperature independent behavior in samples withthe highest values of Tc. They also show no significant change in RH values as a function of oxygen content. Itindicates that, in this range of low oxygen concentration, the improvement of superconducting properties byreducing the oxygen content is produced by structural ordering and not by change in the carrier density.