2015/01/30 by O. E. Ayala-Valenzuela, Ayala-Valenzuela, O. E., N. Haberkorn +9
Physics and Astronomy · #FOS: Physical sciences #Superconductivity (cond-mat.supr-con) #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1501.07677
arxiv created 2015/01/30 · arxiv updated 2015/02/02
We report the magnetic field -- temperature (H-T) phase diagram of Ca10(Pt4As8)[(Fe1-xPtx)2As2]5 (x≈ 0.05) single crystals, which consists of normal, vortex liquid, plastic creep and elastic creep phases. The upper critical field anisotropy is determined by a radio frequency technique via the measurements of magnetic penetration depth, λ. Both, irreversibility line, Hirr(T), and flux creep line, HSPM(T), are obtained by measuring the magnetization. We find that Hirr(T) is well described by the Lindemann criterion with parameters similar to those for cuprates, while small HSPM(T) results in a wide plastic creep regime. The flux creep rates in the elastic creep regime are in qualitative agreement with the collective creep theory for random point defects. A gradual crossover from a single vortex to a bundles regime is observed. Moreover, we obtain λ(4~ \text K) = 260(26) nm through the direct measurement of the London penetration depth by magnetic force microscopy.