  Bi2Sr2-xLaxCaCu2O8+d superconducting whiskers were successfully grown from
Bi-rich meltscontaining various La contents. Effect of La-doping on the whisker
growth, structure and superconductivity has been studied. It has been found
that the whiskers can be grown only from La-doped melts, no whisker was
obtained from the La-free melt x=0. Within the doping region x=0.025-0.3, all
the grown whiskers are of the Bi-2212 pure phase. The c-axis lattice constant
decreases with increasing the La content in the melt. The effect of La doping
on the superconductivity is similar to that of other rare earth dopings in this
system, it depresses and broadens the transition. The melt method used in this
letter is compared with the other two kinds of processes used so far, usual
powder sintering and glassy precursor annealing method. The possible growth
mechanism of the whiskers from the melt method is discussed briefly.
