GROWTH OF Bi-2223 PHASE FROM TEXTURED Bi-2212 PHASE SOLIDIFIED IN HIGH MAGNETIC FIELDS

1)添加Ag_2O、MgO和B_2O_3对Bi-2223相高磁场凝固后组织和超导性能的影响：添加5%MgO和5%Ag_2O对Bi-2223相高磁场凝固后组织略有改善，而添加B2O3对Bi-2223相无改善作用。MgO的加入也提高了由vsm测量的磁滞回线ΔM估算的Jc值。2)高磁场固化Bi-2201相的织构和超导性能：非化学计量Bi-2201相在1OT磁场中固化。得到了一个大的，良好的c轴对齐的Bi-22O1相。在各向异性方面，垂直于外加磁场方向流动的Jc比平行于外加磁场方向流动的Jc大10倍左右。相反，未加磁场固化的Bi-22O1样品没有织构。3)强磁场烧结过程中Bi-2223相的形成与织构：在10T磁场下，烧结温度为835 ~ 860℃。烧结温度达到855℃时，随着烧结温度的升高，Bi-2223相的织构得到改善，但Bi-2223相的体积分数随着烧结温度的升高而降低。在液相存在的条件下，860℃烧结后未得到Bi-2223相，只得到排列良好的Bi-2212相。

1) Effect of Ag_2O,MgO and B_2O_3 additions on microstructure and superconducting properties of Bi-2223 phase after solidification in high magnetic fields:5%MgO and 5%Ag_2O additions improved the texture of Bi-2223 phase slightly after solidification in high magnetic fields but B2O3 addition never improved. MgO addition also improved the Jc value estimated from ΔM of hysteresis loop measured by VSM.2) Texture and superconducting properties of Bi-2201 phase solidified in high magnetic fields:Non-stoichiometric Bi-2201 phase were solidified in a magnetic field of 1OT. A Large, well c-axis aligned Bi-22O1 phase was obtained. As for the anisotropy, Jc flowed perpendicular to the applied magnetic field is about 10 times larger than that flowed parallel to it. On the contrary, no texture was observed in the Bi-22O1 sample solidified without a magnetic field.3) Formation and texture of Bi-2223 phase during sintering in high magnetic fields:Samples were sintered in the temperature range from 835 to 86O℃ in a magnetic field of 10T. Texturing of Bi-2223 phase was improved with increasing sintering temperature up to 855℃, however the volume fraction of Bi-2223 phase decreased with increasing sintering temperature. No Bi-2223 phase was observed after sintering at 860℃ where the liquid phase existed, but only well-aligned Bi-2212 phase was obtained.