Magnetic Compton scattering study of Laves phase ZrFe2 and Sc doped ZrFe2: Experiment and Green function based relativistic calculations

Highlights: • Reported spin momentum densities of ZrFe₂ and Zr_0.8Sc_0.2Fe₂ using magnetic Compton spectrometer. • Discussed site-specific spin moments deduced from magnetic Compton profiles (MCPs). • Derived MCPs, density of states and site-specific spin moments using SPR-KKR method. • Discussed role of orbital moment and covalent magnetism in both the compounds. Spin momentum densities of ferromagnetic ZrFe₂ and Zr_0.8Sc_0.2Fe₂ have been measured using magnetic Compton scattering with 182.65 keV circularly polarized synchrotron radiations. Site specific spin moments, which are responsible for the formation of total spin moment, have been deduced from Compton line shapes. At room temperature, the computed spin moment of ZrFe₂ is found to be slightly higher than that of Sc doped ZrFe₂ which is in consensus with the magnetization data. To compare the experimental data, we have also computed magnetic Compton profiles (MCPs), total and partial spin projected density of states (DOS) and the site specific spin moments using spin-polarized relativistic Korringa-Kohn-Rostoker method. It is observed that the spin moment at Fe site is aligned antiparallel to that of Zr site in both ZrFe₂ and Zr_0.8Sc_0.2Fe₂. The MCP results when compared with vibrating sample magnetometer based magnetization data, show a very small contribution of orbital moment in the formation of total magnetic moments in both the compounds. The DOS of ferromagnetic ground state of ZrFe₂ and Zr_0.8Sc_0.2Fe₂ are interpreted on the basis of a covalent magnetic model beyond the Stoner rigid band model. It appears that on alloying between a magnetic and a non-magnetic partner (with low valence), a polarization develops on the non-magnetic atom which is anti-parallel to that of the magnetic atom.