INVESTIGADORES
HABERKORN Nestor Fabian
artículos
Título:
Increment of the collective pinning energy in Na1-xCaxFe2As2 single crystals with random point defects introduced by proton irradiation
Autor/es:
N. HABERKORN; JEEHOON KIM; B. MAIOROV; I. O. USOV; G. F. CHEN; W. YU; L. CIVALE
Revista:
SUPERCONDUCTOR SCIENCE AND TECHNOLOGY
Editorial:
IOP PUBLISHING LTD
Referencias:
Lugar: Londres; Año: 2014 vol. 27 p. 95004 - 95011
ISSN:
0953-2048
Resumen:
We study the influence of random point defects introduced by 3 MeV proton irradiation (doses 1x1016 and 2x1016cm2) on the vortex dynamics of NaxCa1-xFe2As2 (x=0.5 and x=0.75) single crystals. Our results indicate that the irradiation produces an enhancement of the critical current density and a reduction of the creep rate in vortex relaxation. The plateau in the temperature dependence of vortex creep rate initially present in as grown single crystals disappears after irradiation. This fact can be associated with a large increment of the collective pinning energy from 100 to 350 - 400 K. On the other hand, Maley analysis indicates that after irradiation both samples present a glassy exponent m close to the one expected in the so-called large bundle regime (7/9) for random point defects.
