ELECTRONIC-PROPERTIES OF A NEW CLASS OF ALUMINUM-BASED METALLIC GLASSES - AL100-X-Y(FE,CO,NI,CU)X(LA,Y)Y

摘要

Electrical and Hall resistivity studies have been carried out on a new class of melt-spun, Al-T-R, Al-rich (above 75 at. %) ternary amorphous alloys in order to study the possible correlation between their electronic and enhanced mechanical properties. We find for all these alloys (over 26 of them) the room-temperature Hall coefficient has a negative sign and increases significantly in magnitude with the (T-R) content, which indicates a decrease in the effective carrier concentration. This is consistent with the suggestion that the observed remarkable mechanical properties in these alloys are due to the enhanced strength of the additional local Al-T and AL-R bonds. In these alloys the electrical resistivity at room temperature increases from about 65 μΩ cm for the binary Al90(R)10 amorphous alloys to over 250 μΩ cm on further substitution of Al with less than 15 at. % of T elements. From a systematic study the importance of s-d scattering mechanism and a crossover in the electronic properties from s- to d-band amorphous metal with T substitution are discussed.