The electron structure and site preferences of Zn and Fe cations in Y hexaferrite system were calculated. The hyperfine magnetic fields on Fe-57 nuclei were determined using WIEN2k and corrections for hyperfine contact interaction.
The calculated fields were compared to Fe-57 nuclear magnetic resonance (NMR) experiment in Ba2Zn2Fe12O22 single crystal with an aim of interpretation of experimental NAIR spectrum.