INVESTIGADORES
SERQUIS Adriana Cristina
artículos
Título:
Reduction step and quenching of superconductivity in Nd1.85Ce0.15Cu1.01Oy: A Raman scattering study
Autor/es:
A. FAINSTEIN; A. SERQUIS; R.G. PREGLIASCO; F. PRADO; A. CANEIRO; S. PINOL
Revista:
PHYSICAL REVIEW B
Editorial:
AMER PHYSICAL SOC
Referencias:
Lugar: New York; Año: 2001 vol. 63 p. 1845030 - 1845034
ISSN:
1098-0121
Resumen:
The superconducting properties of the electron doped materials L2-x(Ce,Th)xCuOy (L =Nd, Sm, Pr, and Eu) are extremely sensitive to small variations of the oxygen content. Superconductivity only appears in samples that are quenched under slightly reduced atmospheres, at oxygen partial pressures below a critical value corresponding to the CuO-Cu2O equilibrium. We present a detailed Raman scattering investigation of Nd1.85Ce0.15Cu1+dOy ceramic and single crystalline samples prepared under controlled oxygen content above and below this critical oxygen partial pressure. The Raman scattering spectra show that CuO traces are present in all the samples prepared above the critical partial pressure and discontinuously disappear for the superconducting compounds. These results suggest that CuO might intergrow with the CuO2 planes in these compounds leading to a subtle internal strain-that quenches the superconducting state.
