Observation of crystalline state of the graded structure BiSb alloy prepared under a strong gravitational field of around 1 million G Original Research Article

An atomic-scale graded structure had been formed in an all-proportion miscible alloy in bismuth (Bi)-antimony (Sb) (70:30 in mol%) system by the sedimentation of substitutional solute atoms under a strong gravitational field of 1 million G level in maximum acceleration at 220–240□ (Mashimo et al. 1997, Mashimo et al. 2001). The large and long crystals whose grain sizes were several mm long and several hundreds of μm wide were oriented along the direction of gravity in the high gravity region larger than about 0.7×106 G, while those of the small crystals in the low gravity region smaller than it were several 10 Pin. It was found that the large strain existed in the large crystals by back-reflection Laue method. It was found that the c axis of hexagonal structure of a large crystal was roughly parallel to the direction of gravity by Transmission Electron Microscopy (TEM) observation.