Mössbauer investigations of the FeCoNiPd x and Cr x FeCoNiPd high entropy alloys

Two series of FeCoNiPd_x and Cr_xFeCoNiPd high entropy alloys were investigated using SEM-EDX, XRD technique and Mössbauer spectroscopy. Increasing of Pd content in the FeCoNiPd_x samples only slightly influenced the Mössbauer spectra. They were analysed assuming simultaneous presence of hyperfine field and quadrupole splitting distributions, however random direction of observation relative to $B_{\mathrm{hf}}$ and EFG caused the average QS value to be close to zero. Increasing of Cr content in the Cr_xFeCoNiPd samples resulted in strong decrease of the hyperfine field, its distribution becomes wide and influence of $B_{\mathrm{hf}},\mathrm{IS}\left(B_{\mathrm{hf}}\right)$ and EFG on the Mössbauer spectra can not be separated unambiguously. The decomposing of the HEAs compositions into binary artificial Fe-dopant systems, namely [FeCoNi]-Pd and [FeCoNiPd]-Cr, allowed to interpret the magnetic structure of the two investigated series.