Grain texture and bulk magnetic anisotropy correlation in polycrystalline Bi2Sr2CaCu2O8+δ thin rods

Application of elevated magnetic fields during growth of BiSrCaCuO superconducting whiskers and studies of growth defects for better understanding of the growth mechanism

“…For the BiSrCaCuO un-doped ceramic, 'nucleation and growth' type mechanisms or mechanisms involving a liquid phase are described in the Ref. [45][46][47][48][49][50][51][52][53][54], but several other growth models, such as intercalation, exchange, pipediffusion, one-dimensional diffusion along the caxis, epitaxial growth starting from a primary phase [45][46][47][48][55][56][57][58][59][60][61][62][63][64] were also introduced. Generally, these models are considered to belong to the so-called 'solid-state' growth models, although a clear separation between them or between them and 'nucleation and growth' models is difficult and many articles reported simultaneous occurrence of several mechanisms.…”

Very Large Superconducting Currents Induced by Growth Tailoring

“…During recent years, this radial gradient has been reduced by two different strategies: decreasing the precursor radii 13,14 or the growth speed. 15,16 In the first case, the critical current (I c ) is reduced even if the J c is increased, while in the second case both I c and J c are increased at the cost of a higher processing time, rendering these materials unattractive for practical applications. More recently, a successful modification to the LFZ technique was adapted to reduce the radial gradient avoiding the above inconveniences, by applying a d.c. electrical current during the growth process, termed Electrically Assisted Laser Floating Zone technique (EALFZ).…”

“…One of the main drawbacks of the LFZ technique is that the alignment of the superconducting grains is strongly affected by the radial gradient produced in the growth process, inducing grain misalignment when it is increased. During recent years, this radial gradient has been reduced by two different strategies: decreasing the precursor radii , or the growth speed. , In the first case, the critical current ( I c ) is reduced even if the J c is increased, while in the second case both I c and J c are increased at the cost of a higher processing time, rendering these materials unattractive for practical applications. More recently, a successful modification to the LFZ technique was adapted to reduce the radial gradient avoiding the above inconveniences, by applying a d.c. electrical current during the growth process, termed Electrically Assisted Laser Floating Zone technique (EALFZ). − The application of an electrical current through the crystallization interface induces strong modifications to the ionic mobility in the molten zone and to the temperature gradients at the solid/liquid interface.…”

Review on Bi–Sr–Ca–Cu–O whiskers

“…(1) In the case of whiskers the proposed mechanism is mainly a solid-liquid one and it corresponds to the 'nucleation and growth', 'dissolution and crystallization' or other mechanisms involving liquid phases [74][75][76][77][78][79][80][81][82][83] for the Bibased superconducting phases in the BSCCO system without impurities. At the same time for the BSCCO system without impurities solid-solid type growth mechanisms such as intercalation, exchange, pipe-diffusion, and onedimensional diffusion along the c-axis [74][75][76][77][84][85][86][87][88][89] or 'epitaxial' growth mechanisms [90][91][92][93][94][95] were introduced. Considering that, in the whiskers, intergrowth of Bi-2223 into Bi-2212 structure is frequently detected (especially by transport measurements), it is possible that, to some extent, solid-solid and epitaxial mechanisms are active during whisker growth.…”