Specific features of neutron scattering upon heat treatment of the Co$_{67}$Fe$_{31}$V$_2$ alloy

This paper reports on the results obtained from small-angle neutron scattering investigations during annealing of two plates of the Co$_{67}$Fe$_{31}$V$_2$ alloy under heating the first and second samples to 360 and 500$^\circ$C, respectively, as well as in applied weak magnetic fields ($H\approx$ 3 Oe). To elucidate the role of the vanadium impurity, measurements have also been performed on the Co$_{68}$F$_{32}$ alloy. It has been revealed using neutron diffraction that, at temperatures below 360$^\circ$C, the Fe and Co atoms begin to undergo ordering in the samples, which results in a change in the space group of the crystal structure. With an increase in the temperature, a fine-dispersed phase is formed in the Co$_{67}$Fe$_{31}$V$_2$ alloy, which leads to a qualitative change in the small-angle neutron scattering pattern. It has been found that, after annealing and magnetization ($H >$ 4 kOe) of the second sample, there is a strong difference in the integrated intensities of scattered neutrons for opposite directions of their spins in the primary beam.