Ab-initio calculation of the Hubbard $U$ and Hund exchange $J$ in local moment magnets: The case of Mn-based full Heusler compounds

Abstract

Mn-based full Heusler compounds possess well-defined local atomic Mn moments, and thus the correlation effects between localized d electrons are expected to play an important role in determining the electronic and magnetic properties of these materials. Employing ab-initio calculations in conjunction with the constrained random-phase approximation (cRPA) method, we calculate the strength of the effective on-site Coulomb interaction parameters (Hubbard U and Hund exchange J) in the case of X2MnZ full Heusler compounds with X being one of Ni, Pd or Cu, and Z being one of In, Sn, Sb or Te. We show that the Z element (or sp element) in Heusler compounds significantly reduces the strength of the Hubbard U parameter for Mn 3d electrons compared to the elementary bulk Mn. On the contrary, the effect of the sp-atom on the strength of the U parameter of Ni, Cu or Pd valence d electrons is not so substantial with respect to the elementary bulk values. The U values for all transition metal atoms decrease with increasing sp electron number in the In-Sn-Sb-Te sequence. Our cRPA calculations reveal that despite their well-defined local magnetic moments, the Mn-based full Heusler alloys fall into the category of the weakly correlated materials.

Physical Review Materials, accepted for publication

References in corpus (15)

• Half-metallic ferromagnets: From band structure to many-body effects
• Calculations of Hubbard U from first-principles
• First principles study of the multiferroics BiFeO${}_3$, Bi${}_2$FeCrO${}_6$, and BiCrO${}_3$: Structure, polarization, and magnetic ordering temperature
• Screened Coulomb interaction in the maximally localized Wannier basis
• Efficient implementation of the GW approximation within the all-electron FLAPW method
• Role of the conduction electrons in mediating exchange interactions in Heusler alloys
• Dynamical mean-field theory using Wannier functions: a flexible route to electronic structure calculations of strongly correlated materials
• Maximally Localized Wannier Functions within the FLAPW formalism
• Combining DFT and Many-Body Methods to Understand Correlated Materials
• Wannier-function approach to spin excitations in solids
• Effective Onsite Interaction for Dynamical Mean-Field Theory
• Method for calculating the electronic structure of correlated materials from a truly first-principles LDA+U scheme
• Theoretical investigation into the possibility of very large moments in Fe16N2
• Renormalization of effective interactions in a negative charge-transfer insulator
• Electronic correlations in the semiconducting half-Heusler compound FeVSb

Cited by in corpus (2)

• Magnetic States and Electronic Properties of Manganese-Based Intermetallic Compounds Mn${}_2$YAl and Mn${}_3$Z (Y = V, Cr, Fe, Co, Ni; Z = Al, Ge, Sn, Si, Pt)
• First-principles prediction of energy band gaps in 18-valence electron semiconducting half-Heusler compounds: Exploring the role of exchange and correlation