Spin and orbital polarization in layered rare-earth-manganese ternary intermetallic compounds

Abstract

We report the results of ab initio energy-band calculations for the ternary intermetallic compound GdMn6Ge6. The ferrimagnetic arrangement of Gd and Mn magnetic sublattices is reproduced as well as the average moment per Mn atom. The comparatively low strength of the Gd-Mn effective exchange coupling and the occurrence of a weak orbital polarization (3%) at the manganese sites are further results of this analysis. The numerical results are compared with prior magnetization and hyperfine-field analyses.

Filling the CoSn host-cell: the HfFe6Ge6-type and the related structures

“…Since the Sn atomic size is larger than the Ge atomic size, the Mn--M distances are longer in stannides than in germanides. The decrease of z Mn in stannides 516 G. Venturini enables a tightening of the Mn--M contacts thus accounting for a significant bonding between these two species as suggested by electronic structure calculations [25][26][27].…”

Magnetic and transport properties of HfFe6Ge6-type REMn6X6−X′ solid solutions (RE = rare earth; X = Ge, Sn; X′ =Ga, In)

“…Moreover, some theoretical studies have been conducted through electronic structure calculations [22,23].…”

Magnetic ordering of TbMn2D2- a nuclear magnetic resonance analysis

“…On the other hand, we have established by a comprehensive experimental and theoretical analysis of the magnetism of RMn 6 Ge 6 intermetallic compounds, that their high-temperature magnetic ordering is due to the manganese sublattices [7][8][9]. The rare earth moments are primarily polarized via 3d-5d wave function extension and hybridization, followed by ferromagnetic Hund's rule rare earth 5d-4f exchange [9].…”

“…On the other hand, we have established by a comprehensive experimental and theoretical analysis of the magnetism of RMn 6 Ge 6 intermetallic compounds, that their high-temperature magnetic ordering is due to the manganese sublattices [7][8][9]. The rare earth moments are primarily polarized via 3d-5d wave function extension and hybridization, followed by ferromagnetic Hund's rule rare earth 5d-4f exchange [9]. The R-R exchange interaction of RKKY type [10] and crystal field effects are at the origin of the frequently observed complicated magnetic structures at low temperature, but R-R exchange interaction without R-Mn coupling would generate R sublattice magnetic ordering at substantially lower temperatures than the Mn-sublattice ordering, only [7,9].…”

“…The rare earth moments are primarily polarized via 3d-5d wave function extension and hybridization, followed by ferromagnetic Hund's rule rare earth 5d-4f exchange [9]. The R-R exchange interaction of RKKY type [10] and crystal field effects are at the origin of the frequently observed complicated magnetic structures at low temperature, but R-R exchange interaction without R-Mn coupling would generate R sublattice magnetic ordering at substantially lower temperatures than the Mn-sublattice ordering, only [7,9]. For the RMn 6 Ge 6 ternary intermetallic compounds, the Mn-R exchange interaction is comparatively weak and the coupling constant falls only in the 1-10 K range [9], polarizing the R sublattice ferrimagnetically already above its own ordering temperature.…”