Interfacially Mediated Synthesis of High Tc Superconductors in Single Compartment Vesicles (Expedited Award)

一种生产均匀、超细（~ 100 A）、 提出了一种致密、单分散的超导陶瓷， 快速奖励 该方法利用了单个 隔室囊泡之间形成高度选择性的屏障， 外部和内部，从而在内部形成微体积反应器。 囊内间隙 通过适当的处理， 混合的金属氢氧化物（超导体的前体， 陶瓷）可以在这些囊泡的内部区域被诱导 只. 一种混合金属氯化物溶液， Cu++、Cu+、Ba++和Y+离子的比例沿着，约为1% w/w 二棕榈酰磷脂酰胆碱将在略高于 脂质凝胶-液相转变温度以包封一些 单层囊泡内的金属和氯离子。 这项建议是首次尝试使用单室 用于共沉淀作为前体的金属氢氧化物的囊泡 最近发现的高温超导陶瓷。 临界转变温度和临界磁性 场强与化学计量密切相关， 陶瓷相的组成。 这些可以很容易地在 提出的技术，通过改变阳离子的比例， 原始解决方案 相反，临界电流密度 取决于用于获得最终产品的加工步骤。 通过生产超细、致密和均匀的颗粒， 比目前可用的更高的临界电流密度 将获得烧结的超导陶瓷。

A novel technique for the production of uniform, ultrafine (~100A), dense, monodispersed superconducting ceramics is proposed in this expedited award. This method exploits the ability of single compartment vesicles to form a highly selective barrier between its exterior and interior, thus creating a microvolume reactor in the intravesicular space. By appropriate processing, coprecipitation of the mixed metal hydroxides (precursors of the superconducting, ceramics) can be induced in the internal region of these vesicles only. A mixed metal chloride solution consisting of precalculated ratios of Cu++, Cu+, Ba++, and Y+++ ions along with ~1% w/w dipalmitoyl phosphatidylcholine will be sonicated at slightly above the lipid gel-liquid phase transition temperature to encapsulate some of the metal and chloride ions inside the unilamellar vesicles. This proposal represents the first attempt at using single compartment vesicles for coprecipitation of metal hydroxides which are precursors for the recently discovered high temperature superconducting ceramics. The critical transition temperature as well as the critical magnetic field strength are intimately related to the stoichiometry and composition of the ceramic phase. These can be varied easily in the proposed technique by changing the ratio of the cations in the original solution. In contrast, however, the critical current density depends upon the processing steps used to obtain the final product. By producing ultrafine, dense and uniform particles, it is expected that higher critical current density than the presently available sintered superconducting ceramics will be obtained.