  Superconducting magnesium diboride has been prepared with intra-granular TiB
precipitates that have appropriate size and spacing for the pinning of
superconducting vortices. The TiB particles have a size ranging from 1 nm to 20
nm and a spacing about 5 times as large. By co-depositing Ti and B on a
commercial carbon coated silicon carbide substrate with chemical vapor
deposition methods, it was possible to obtain a starting fiber with Ti well
dispersed in the B. Reacting these fibers in a Mg vapor then transformed the
fiber into a superconductor capable of carrying 10,000 A/cm^2 at 25K and 1 T.
The Ti-B bonds are strong enough that there is relatively little migration of
the Ti as the MgB2 grains form around the TiB precipitates. TiB2 precipitates,
if they are present, can not be seen in the selected area diffraction pictures
that show the TiB precipitates.
