High-pressure effects in fluorinatedM. Monteverde1, 2, C. Acha2, M. Núñez-Regueiro1, D. A. Pavlov3, K. A. Lokshin3, S. N. Putilin3 and E. V. Antipov3
1 CRTBT, CNRS - BP166, 38042 Grenoble Cedex 09, France
2 Laboratorio de Bajas Temperaturas, Departamento de Física, FCEyN Universidad de Buenos Aires, Ciudad Universitaria (C1428EHA) Buenos Aires, Argentina
3 Department of Chemistry, Moscow State University - Moscow 119992, Russia
received 25 April 2005; accepted 7 September 2005
published online 30 September 2005
We have measured the pressure sensitivity of Tc in fluorinated (Hg-1223) ceramic samples with different F contents, applying pressures up to 30. We obtained that Tc increases with increasing pressure, reaching different maximum values, depending on the F doping level, and decreases for a further increase of pressure. A new high Tc record ( ) was achieved by applying pressure (23) in a fluorinated Hg-1223 sample near the optimum doping level. Our results show that all our samples are at the optimal doping, and that fluorine incorporation decreases the crystallographic a-parameter concomitantly increasing the maximum attainable Tc. This effect reveals that the compression of the a-axis is one of the keys that controls the Tc of high-temperature superconductors.
74.72.Jt - Other cuprates, including Tl and Hg-based cuprates.
74.62.Fj - Pressure effects.
© EDP Sciences 2005