Magnetic microstructure on surface and in bulk of NANOPERM-type nanocrystalline alloys: Mössbauer effect studies

NANOPERM-type nanocrystalline alloys depict relatively simple Mössbauer spectra, thus enabling model studies of the influence of nanocrystallites on surface and bulk properties. Using FeMXB (M=Mo, Nb, Ti; X=Cu, Au) master alloys, we discuss the crystallization behaviour as well as distributions of hyperfine magnetic fields as a function of the annealing temperature (i.e., the amount of nanograins). Microstructure and magnetic arrangement is reviewed for the surface regions down to a depth of about 100 nm and for the bulk of the investigated specimens adopting conversion electron Mössbauer spectroscopy and transmission Mössbauer spectroscopy, respectively.