Sudershan, YS and Rastogi, Amit and Bhat, SV and Grover, AK and Yamaguchi, Y and Oka, K and Nishihara, Y (1998) Vortex dynamics at rf frequencies in Bi2Sr2CaCu2O8 single crystals. In: Physica C: Superconductivity, 297 (3-4). pp. 253-261.
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We have studied the low magnetic field high temperature region of the H-T phase diagram of Bi2Sr2CaCu2O8 single crystals using the technique of non-resonant rf response at a frequency of 20 MHz. With H(rf)parallel to a, H parallel to c, the isothermal magnetic field scans below T-c show that the frequency f(H) of the tank circuit decreases continuously with increase in H before saturating at H similar to H-D(T). Such a decrease in f(H) reflects increasing rf penetration into the weakly screened region between CuO bilayers. The saturation of f(H) at its lowest value for H similar to H-D(T) indicates complete rf penetration land hence the disappearance of field dependence) due to the vanishing of the screening rf currents I-rf(c) in those regions or equivalently when the phase coherence between adjacent superconducting layers vanishes. Therefore H,(T) represents the decoupling of the adjacent superconducting bilayers, and hence also a 3D to 2D decoupling transition of the vortex structure. Simultaneous monitoring of the field dependent rf power dissipation P(H) shows a maximum in dP/dH at H-D(T). The observed H-D(T) line in many crystals is in excellent agreement with the (l/t-1) behavior proposed for decoupling.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Elsevier Science.|
|Keywords:||Bi2212;rf absorption;vortex decoupling;H-T phase diagram.|
|Department/Centre:||Division of Physical & Mathematical Sciences > Physics|
|Date Deposited:||31 Dec 2009 07:19|
|Last Modified:||19 Sep 2010 05:28|
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