Intrinsically weak magnetic anisotropy of cerium in potential hard-magnetic intermetallics

Abstract

Cerium-based intermetallics are currently attracting much interest as a possible alternative to existing high-performance magnets containing scarce heavy rare-earth elements. However, the intrinsic magnetic properties of Ce in these systems are poorly understood due to the difficulty of a quantitative description of the Kondo effect, a many-body phenomenon where conduction electrons screen out the Ce-4f moment. Here, we show that the Ce-4f shell in Ce-Fe intermetallics is partially Kondo screened. The Kondo scale is dramatically enhanced by nitrogen interstitials completely suppressing the Ce-4f contribution to the magnetic anisotropy, in striking contrast to the effect of nitrogenation in isostructural intermetallics containing other rare-earth elements. We determine the full temperature dependence of the Ce-4f single-ion anisotropy and show that even unscreened Ce-4f moments contribute little to the room-temperature intrinsic magnetic hardness. Our study thus establishes fundamental constraints on the potential of cerium-based permanent magnet intermetallics.

References in corpus (19)

• Electronic Structure Calculations with Dynamical Mean-Field Theory: A Spectral Density Functional Approach
• Continuous-time Monte Carlo methods for quantum impurity models
• A continuous-time solver for quantum impurity models
• Ab initio calculations of quasiparticle band structure in correlated systems: LDA++ approach
• First-principles Calculations of the Electronic Structure and Spectra of Strongly Correlated Systems: Dynamical Mean-field Theory
• TRIQS: A Toolbox for Research on Interacting Quantum Systems
• Dynamical Mean-Field Theory within an Augmented Plane-Wave Framework: Assessing Electronic Correlations in the Iron Pnictide LaFeAsO
• TRIQS/DFTTools: A TRIQS application for ab initio calculations of correlated materials
• Self-consistency over the charge-density in dynamical mean-field theory: a linear muffin-tin implementation and some physical implications
• Importance of electronic correlations for structural and magnetic properties of the iron pnictide superconductor LaFeAsO
• Strongly Correlated Electron Materials: Dynamical Mean-Field Theory and Electronic Structure
• Quantum Theory of Rare-Earth Magnets
• Quantum phase transitions in heavy fermion metals and Kondo insulators
• First-principles study on stability and magnetism of NdFe11M and NdFe11MN for M=Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn
• Crystal field splittings in rare earth-based hard magnets: an ab initio approach
• Intrinsic magnetic properties of {$R$(Fe${}_{1-x}$Co${}_x$)${}_{11}$Ti$Z$} ($R$ = Y and Ce; $Z$ = H, C, and N)
• Electronic structure of the strongly hybridized ferromagnet CeFe2
• Relevance of $4f$-$3d$ exchange to finite-temperature magnetism of rare-earth permanent magnets: an ab-initio-based spin model approach for NdFe${}_{12}$N
• Combining electronic structure and many-body theory with large data-bases: a method for predicting the nature of 4f states in Ce compounds

Cited by in corpus (2)

• Evolution of Magnetism in Magnetic Topological Semimetal NdSb${}_x$Te${}_{2-x+\delta }$
• Effect of transition metal doping on magnetic hardness of CeFe${}_{12}$-based compounds