The Hyperfine Parameters for 57Fe in Fe-V Alloys
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Abstract
The hyperfine parameters for 57Fe in Fe1-xVx(0 ≤ x ≤ 0.843) alloy systems have been studied by means of Mossbauer spectroscopy. For x<0.1 the hyperfine field Hhf(n, x) and the isomer shift IS(n, x) on Fe site with the number of V atoms in the vicinity of the Fe nuclein and V concentration x can be described by the following equations;
Hhf(n,x)=(331-n·ΔHhf)+k1x
IS(n,x)=-n·ΔIS+k2x
Where △Hhf and △IS, the change in the hyperfine field and isomer shift found per one V atom in the neighbour shell, are 24.5kOe and 0.016 mm/s, respectively. These expression indicate that the influence of V atoms on the hyperfine field and isomer shift can be divided into two parts: short range effect and long range effect. The former, the effect of the neighboured V atoms, is additive. The later is attributed to the expansion of lattice. In the Fe1-xVx(0≤x≤0.843) alloys the hyperfine field distributions and the average value of hyperfine field and isomer shift are obtained. The average isomer shift as a function of V concen-tration x can be written as follow:
IS= -0.19x
The hyperfine field distributions show that two state of Fe atoms seem to exist in the Fe1-xVx alloys for x≥0.5.
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