The crystal fraction determination of the nanocrystalline phase transformed from the Fe-base amorphous matrix using EXAFS

Abstract

Amorphous ribbons with composition of Fe73.5Cu1Nb3Si13.5B9 (FINEMET) were annealed between 427 and 627degreesC. This annealing process made a series of partially crystallized samples with different crystal sizes and fractions. The nanocrystalline structure of alpha-Fe (Si) embedded in an amorphous matrix was investigated by synchrotron radiation X-ray diffraction (SR-XRD). The crystal fractions of each sample were measured by the thermal analysis. It shows an 'S' shape curve of typical transformation phenomena. The fraction was also obtained from extended X-ray absorption fine structure (EXAFS) analysis. The result from EXAFS analysis agrees with the thermal analysis very well. There was a little difference about 1-3% between EXAFS and thermal analysis. (C) 2003 Elsevier B.V. All rights reserved.