Magnetic field penetration in YBa₂Cu₃O_7-δsingle crystals under conditions of a reduced surface barrier

Abstract

Using a magneto-optic technique, we have studied field penetration in a sample consisting of several YBCO single crystals merged together on their basal plane. The bending of field stream lines around crystal edges in such a geometry creates an orientation of the local applied field that is nearly perpendicular to the sample surface and thus results in an almost surface-barrier-free field penetration. The penetration field was measured under conditions of a fully developed and a reduced surface barrier, and the values obtained were compared in these two cases. The results obtained show that the surface barrier causes a substantial delay of field penetration in YBCO single crystals over the whole temperature range.

Effects of B2O3 addition on the properties of melt-processed YBa2Cu3O7−δ

“…Magnetization loops and the ac susceptibility (χ) at different temperatures and fields in the samples were obtained using the magneto-optic technique (MO) and a SQUID magnetometer from Quantum Design. Details of the MO technique and the one established at UME-Gebze were described in [12]. The MO technique has quite high spatial resolution to evaluate the values of T c and J c locally even in single grains with some approximations [12,13].…”

“…Details of the MO technique and the one established at UME-Gebze were described in [12]. The MO technique has quite high spatial resolution to evaluate the values of T c and J c locally even in single grains with some approximations [12,13]. The intragranular J c values were obtained by using the one-dimensional Maxwell equation,…”

Simple recipe to synthesize single-domain BaFe12O19 with high saturation magnetization

“…The technique is based on dissolution of initial oxides in ammonium nitrate melt (ANM). Some ceramic oxides, including soft magnetic material YIG (Y 3 Fe 5 O 12 ) [8] which is widely used in magneto-optical applications [9][10][11] and superconductors like YBCO and BSCCO [12,13], were prepared with this method. Using liquid medium to mix initial oxides (or constitutes) on an ionic level is the common point in both ANM and others techniques mentioned above.…”

Enhancement of the irreversibility line inYBa2Cu3O6.95single crystals patterned by heavy ion lithography

“…Generally, a large gap between the indicator film and the current source plane causes loss of both the signal contrast and the spatial resolution. 25,26 The ability to detect and to distinguish the stray field generated by sources at different distances from the measurement plane is important for the following analysis.…”