High-pressure Mössbauer studies of amorphous and crystallineFe3B and(Fe0.25Ni0.75)3B

The pressure dependence of the ${}_{}{}^{57}{}_{}{}^{}\mathrm{Fe}$ hyperfine parameters in amorphous and crystalline ${\left({\mathrm{Fe}}_{1-x}{\mathrm{Ni}}_x\right)}_3\mathrm{B}$ alloys ($x=0\mathrm{} \mathrm{and} 0.75$) were measured by Mössbauer spectroscopy. A similar response of all hyperfine parameters for both the amorphous and crystalline phases with decreasing volume was observed. The pressure dependence of the hyperfine field indicates that the distribution of Fe-B interatomic distances is about two times narrower than that of the Fe-Fe interatomic distances measured by x-ray scattering.