STRUCTURAL AND ELECTRICAL-TRANSPORT PROPERTIES OF AL-CU-CR QUASI-CRYSTALS

Transport properties of quasicrystals in rapidly solidified as well as heat-treated Al65CU20Cr15 alloys were studied over a wide temperature range as a function of structure and microstructure. The characteriza tion was done using x-ray diffraction, transmission electron microscop y and differential scanning calorimetry. Particular attention was paid to primitive to face-centered quasicrystalline transformation which o ccurs on annealing and the effect of microstructures on the transport behavior. The temperature dependence of resistivity is found to depend crucially on the microstructure of the alloy. Further, ordering enhan ces the negative temperature coefficient of resistivity. The low-tempe rature (T less than or equal to 25 K) resistivity of Al65Cu20Cr15 has been compared with that of Al63.5Cu24.5Fe12 alloy. In this region p(T) can be well described by a root T contribution arising from electron- electron interaction. We discuss our results in view of current theori es.