Preparation and characterization of nanocrystalline Nb3Al alloy

The nanocrystalline Nb3Al is prepared by the gas condensation method. The n anocrystalline Nb3Al size with injected 0.1mbar helium pressure is about 15 nm. During the gas condensation process, the superconductivity disappears a t as-prepared NC Nb,AI with the mean particle size about 15 nm. After annea ling the as-prepared NC Nb3Al at 500 degreesC for 30 minutes, the mean part icle size of NC Nb3Al is about 30 nm and the superconductivity appear with T-c about 16K. The results show that superconductivity can be achieved in n anocrystals with a rather smaller size than the typical penetration length of magnetic field. Further study of the influence of gas: condensation allo ying at high magnetic fields is crucial to the understanding of the superco nductivity properties of NC Nb3Al. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.