Bose-glass melting in the cubic (K,Ba)BiO3 high-Tc oxide with columnar defects
Résumé
The Bose-glass transition in the fully isotropic (K,Ba)BiO3 superconductor with columnar defects produced by irradiation with 7.2 GeV Ta ions was studied by transport and nonlinear susceptibility measurements. For fields smaller than the dose equivalent field Bφ, the Bose-glass transition line HBG(T) shifts progressively upwards with increasing dose, dHBG/dT∼1+αBφ1/2. The critical exponents have been deduced from the scaling properties of the transport measurements; we obtain z = 5.3±0.3 and ν=1.1±0.2. For tilted magnetic fields, the transition temperature scales as TBG(0)-TBG(θ)∼/sin(θ)1/ν, as recently suggested by Lidmar and Wallin. ©2000 The American Physical Society.