Preparation of Hg based superconducting wire by solution spinning method.

研究了溶液纺丝法制备汞基超导丝的方法，采用溶液纺丝法制备汞基超导丝，分别用Ba2+、Sr2+、Ca2+、Cu3+、高氯酸铵、聚乙烯醇和有机酸的混合水溶液进行干法纺丝。拉伸后的直径为250微米的长丝经过热解去除挥发性成分，然后进行焙烧。灯丝在真空熔融石英中与Hg1(Ba，Sr)2Ca1Cu2RE&lt；0.1&gt；Ox或Hg1(Ba，Sr)2Ca2Cu3RE&lt；0.2&gt；Ox反应，通过控制加热条件，重新加入制备了单相Hg1212(1)或Hg1223(2)超导体。(1)和(2)单丝的T_c分别为93K和127K，在77K和0T时的J_c分别为2300A/cm~2和1000A/cm~2。用含BaF_2的芯块对F掺杂的HgxBa2Cu3RE_y和0.2&gt；O_y超导体进行了增强J_c的试验。在O_2气流中经350ﾟC的后退火可提高J_c。在高达10T的磁场中，研究了氟对77K下掺氟Hg1223灯丝输运J_c的影响。F掺杂使Hg1223灯丝形成致密的液晶线织构，J_c随磁场的变化明显改善。通过控制加热条件和添加微量HgCl2，在77K和0T下测得最大Jc值为10^4A/cm2。

We have studied the preparation of Hg based superconducting wire by solution spinning method.Long precursor filaments were prepared by dry spinning through a homogeneous aqueous solution mixed acetates of Ba, Sr, Ca and Cu, ammonium perrhenate, poly (vinyl alcohol) and organic acids. The as-drawn filament with a diameter of 250 mum was pyrolyzed to remove volatile components and then calcined. The filaments reacted in an evacuated fused quartz with a pellet of Hg_1 (Ba, Sr) _2Ca_1Cu_2Re_<0.1>O_x or Hg_1 (Ba, Sr) _2Ca_2Cu_3Re_<0.2>O_x. A single phase of filamentary Hg1212 (1) or Hg1223 (2) superconductor is prepared with Re addition by controlling the heating condition. The T_c of the (1) and (2) filaments is 93 K and 127 K and J_c at 77K and 0 T is 2300A/cm^2 and 1000A/cm^2, respectively.A superconducting F-doped Hg_xBa_2Cu_3Re_<0.2>O_y filament was examined to enhance the J_c by using a pellet containing BaF_2. The J_c of the specimens was enhanced by post-annealing up to 350ﾟC in O_2 flow. The influence of fluorine on the transport J_c of the F-doped Hg1223 filament at 77K was examined in magnetic fields of up to 10 T.F-doping resulted in a formation of dense liquidus texture and marked improvement in the field dependence of J_c for the filament. A J_c of more than 10^2A/cm^2 was maintained at 77 K in a field of 10 T.By controlling the heating condition and addition of a trace HgCl_2, a maximum J_c value of 10^4A/cm^2 at 77 K and 0 T was measured.