Flux pinning and dynamical critical fields in some YBaCuO compounds

Review of the critical current densities and magnetic irreversibilities in high Tc superconductors

“…It is indeed found that for spin glasses the general curve shapes depend strongly on the shape of the sample as well as on the material itself but equation (66b) relating Xfc, Xzfc and M~is conserved. depend experimentally on frequency [84][85][86][87][88][89][90][91][92][93][94][95][385][386][387][388] (see also next section). A second aspect also completely neglected in the preceding sections (for the sake of simplicity) In some frequency regions, as in the TAFF limit and close to the depinuing line, the interplay between the two is very severe.…”

Пространственные Характеристики Сверхпроводников И 3d-Холловский Микроскоп Для Их Исследования

“…Динамический диапазон предложенного микроскопа по магнитному полю составляет ±(1−3) • 10 3 G, а по температуре -(2−300) K. Стабильность величин заданного магнитного поля и температуры лучше, чем 10−5 G и 10 −2 K соответственно. Известно, что слабые магнитные поля величиной ∼ 10 −4 −10 −3 G проникают в керамические ВТСП [13,14]. Как показали исследования Рис.…”

Complex susceptibility of superconducting BiPbSrCaCuO ceramics fabricated through combined magnetic melt texturing and hot pressing

“…The pinning of flux lines by defects or impurities in a superconductor is very efficient at low temperatures, are obtained without d.c. fields in the (h ac , T ) plane by studying the field dependence of T p versus applied a.c. field h ac = h irr and give the a.c. IL. The a.c. IL has been the subject of much less theoretical and experimental work, but such a technique is very sensitive to structural details since the peak temperature shifts induced by a.c. fields are much stronger than those induced by d.c. fields of similar amplitude [3,4]. The use of 'high' a.c. fields (h ac up to about 10 2 Oe) leads furthermore to a splitting of the intergranular and intragranular contribution, allowing in this case a determination of the intragranular shift with a good accuracy [2].…”