Investigations on the Anisotropic g Factors of the Ni³⁺Site in La₂Ni_0.5Li_0.5O₄

Abstract

The anisotropic g factors g and g ⊥ of La2Ni0.5Li0.5O4 are theoretically investigated using the perturbation formulae of the g factors for a low spin (S = 1/2) 3d 7 ion in tetragonally elongated octahedra. The studied Ni 3+ (3d 7 ) center arises from the original Ni 2+ capturing one hole by Li + doping. The positive anisotropy ∆g (= g ⊥ − g ) can be ascribed to the lowest 2 A1g state due to the obvious (about 0.14 Å) tetragonal elongation of the oxygen octahedron around the Ni 3+ site via the JahnTeller eect, and the eective magnetic moment is also interpreted in a uniform way. The calculated results show good agreement with the experimental data, and the imperfection of the previous studies based on various adjusted tetragonal energy splittings without correlating to the local structure of the magnetic center is thus overcome in this work.

Investigations of the temperature-dependent electron paramagnetic resonance spectra and local structures for a cobalt(II) porphyrin complex within a metal–organic framework

“…As determined from the properties of the g factors for PCN-224Co 2+ with CO (Gallagher et al, 2017) and other similar 3d 7 centers (Wu et al, 2009;Kuang et al, 2013;Hu et al, 2010;Zhang et al, 2009), the present systems can be described as tetragonally elongated octahedral 3d 7 clusters with low spin (S = 1 2 ). The original cubic ground-orbital doublet 2 E 2g will split into two orbital singlets 2 A 1g () (jd z 2 i) and 2 A 1g 0 ð"Þ ðjd x 2 Ày 2 iÞ (see Fig.…”

“…In the calculation process, the perturbation method is adopted to study the EPR parameters, which has been proved suitable in this area (Wu et al, 2009;Kuang et al, 2013;Hu et al, 2010;Zhang et al, 2009). Unlike these previous reports, the present work includes the effects of different temperatures and mixed ligands.…”

Defect Structures, Electronic Properties, UV–Vis, and EPR Parameters for Rh2+ Centers in LiD: A DFT Study

“…4d 7 (Rh 2+ ) ions in ideal octahedra show the ground orbital doublet 2 E g (t 2g 6 e g ) . When the ligand octahedron is elongated or compressed due to the Jahn‐Teller effect, the original 2 E g can be split into two orbital singlets 2 B 1g (ϵ) and 2 A 1 (θ), with the latter or former lying lowest .…”

“…4d 7 (Rh 2þ ) ions in ideal octahedra show the ground orbital doublet 2 E g (t 2g 6 e g ). [57][58][59] When the ligand octahedron is elongated or compressed due to the Jahn-Teller effect, the original 2 E g can be split into two orbital singlets 2 B 1g (e) and 2 A 1 (θ), with the latter or former lying lowest. [52] Further orthorhombic (D 2 ) distortion may split the related excited states 4 T 1 [t 2 5 e 2 ( 3 A 2 )], 2 T 1 [t 2 5 e 2 ( 3 A 2 )], 2 T 1 [t 2 5 e 2 ( 1 E)], 2 T 2 [t 2 5 e 2 ( 1 E)], and 2 T 2 [t 2 5 e 2 ( 1 A 1 )] into three orbital singlets A 2g , B 1g and B 2g .…”

DFT calculations of the defect structures, electronic structures, and EPR parameters for three Rh2+ centers in AgCl

“…The 4d 7 (Rh 2+ ) ions in ideal octahedra would exhibit the ground orbital doublet 2 E g (t 2g 6 e g ). [34,39,40] When the ligand octahedron is elongated or compressed due to the Jahn-Teller effect, the original 2 E g ground state may be separated into two orbital singlets 2 B 1g and 2 A 1g , with the latter or former being the lowest level. [15,36] [41] The observed EPR parameters yield the negative and positive anisotropies Δg = g //g ⊥ or g z -(g x + g y ) / 2 for T E (or O E ) and T C centers, [10,11] corresponding to the lowest 2 A 1g (or 2 A 1g ′) and 2 B 1g .…”