Structure of Amorphous(Co,Mn)76B24-and (Co,Mn)85B15-Alloys by Means of X-Ray- and Neutron-Diffraction

Abstract

Amorphous (Co1-xMnx)85B15 - (x = 0.07; 0.22; 0.39) and (Co1-xMnx)76B24- (x = 0; 0.07; 0.22) alloys were produced by melt-spinning and investigated by X-ray- and neutron-diffraction. The variation of x, i.e. the manganese concentration did not influence the X-ray intensity pattern, which suggests that no larger topological changes in the structure took place. However, using neutrons, the variation of x caused large intensity variations. These lead for large x to negative values in the total pair distribution functions g(R). From this behaviour it is concluded that cobalt and manganese cannot be mutually substituted but form a chemical short range order with preference for Co-Mn-pairs compared to Mn-Mn- and Co-Co-pairs. The metal-boron-correlations are preferentially cobalt-boron-correlations. The evaluation of measured data yielded no direct boron-boron-contacts.