Zq. Liu et al., Study on the diffraction patterns of alpha ''-Fe16N2 with Jack-1 and Jack-2 structural parameters, J MAT SCI T, 16(4), 2000, pp. 362-366
Two body centered tetragonal (bct) crystal structures of alpha"-Fe16N2 with
x=0.25, z=0.3125 (Jack-1) and x=0.222, z=0.306 (Jack-2) respectively, were
analyzed theoretically with EMS software package. The simulation of diffra
ction patterns indicates that both diffraction patterns of the same axis in
these two structures obey bcc extinction rule. The conclusion is also obta
ined from the analyses of the diffracted waves. alpha"-Fe16N2 precipitates
in the diffusion layer of ion-nitrided alpha-iron have been studied with tr
ansmission electron microscope (TEM). We have distinctly observed the elect
ron diffraction patterns of alpha"-Fe16N2 in [100], [111], [110], [011], [2
10], [021], [311], [113], [331] and [133] zone axes with perfect symmetry,
which indicate the parallel orientation relationship with alpha matrix: <00
1>(alpha")//<001>(alpha), {100}(alpha")// {100}(alpha). The analyses of dif
fraction patterns, which obey bcc extinction rule, verify the bet structure
of alpha"-Fe16N2 discovered by X-ray diffraction.