Jm. Barandiaran et al., RESISTIVITY CHANGES OF SOME AMORPHOUS-ALLOYS UNDERGOING NANOCRYSTALLIZATION, Solid state communications, 88(1), 1993, pp. 75-80
The electrical resistivity of amorphous alloys with compositions: Fe73
.5Nb3Cu1Si13.5B9, Fe86Zr7Cu1B6 and Co80Nb8B12 has been studied in the
temperature range from 300 to 1100K, where crystallization occurs. The
products of crystallization and the grain size have been studied by X
-ray diffraction. In a first step, all the alloys crystallize with sma
ll grains of a few nanometers in diameter (nanocrystalline state), and
the resistivity behavior at this process accounts for the difference
between the amorphous and nanocrystalline phases. The nanocrystalline
phases are: alpha-Fe-Si, alpha-Fe and fcc Co for the three compounds s
tudied respectively. A second process, at which grain growth and preci
pitation of intermetallic compounds and borides takes place, has been
found for all the alloys. The resistivity is sensitive, not only to th
e total transformed sample amount, but to the topological distribution
of the crystalline phases, and therefore shows a more complex behavio
r than other well established techniques, as differential scanning cal
orimetry. This supplementary information given by the resistivity is a
lso discussed.