Critical current enhancement by neutron irradiation of rapidly textured Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8/
The authors have investigated the effect of fast neutron irradiation on c-axis-aligned Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8/ (Bi2212) produced using a new technique. Amorphous Bi2212 was crystallized under 20 MPa uniaxial stress at 870 degrees C for 6 h. DC superconducting quantum interference device (SQUID) shows a transition onset of 90 K. Material was cut into 2*2*0.150 mm slabs, sealed in quartz ampules, and irradiated at fluences of 10/sup 16/, 5*10/sup 16/, 2.5*10/sup 17/, and 7*10/sup 17/ n/cm/sup 2/. DC SQUID results show that critical current density, J/sub c/, is increased by a factor of 2.5 at 10 K for fluences of 7.2*10/sup 17/ for H parallel to c-axis for fields less than 3 T. The higher the fluence, the lower the dependency of J/sub c/ on applied field and temperature. Critical temperature, T/sub c/, decreased by 1 K for a fluence of 2.5*10/sup 17/ n/cm/sup 2/ with an additional 2 K drop for 7.2*10/sup 17/ n/cm/sup 2/. The increase in the width of the high field hysteresis loops for increasing fluence is more pronounced for samples measured normal to the c-axis.<<ETX>>