Magnetic Hyperfine Fields in Lu $$_2$$ 2 V $$_2$$ 2 O $$_7$$ 7 : A Model Approach

Abstract

We report a theoretical approach to the investigation of the magnetic hyperfine interaction on the 51 V nucleus in Lu 2 V 2 O 7 with the view of understanding the orbital ordering pattern in this compound. First, we have evaluated the vanadium 3d 1 -level splitting ( ) under the crystal field with the D 3d -symmetry using the point charges approximation. Second, we have calculated the exchange interaction constant (J) using the ab initio approach. It is shown that the crystal field energy is much stronger than the exchange interaction one and hence the orbital liquid state cannot occur in Lu 2 V 2 O 7 . Finally we have analyzed the magnetic hyperfine field affecting the vanadium nucleus leaning upon these results.

Influence of structure effects and orbital ordering on the magnetic hyperfine field in pyrochlore oxides R2V2O7 (R = Lu, Yb, Tm, Er, Ho): ab initio calculations

“…It allows us to conclude that the orbital ordering determines a large anisotropy of magnetic hyperfine fields in R 2 V 2 O 7 . This result agrees with our earlier studies of Lu 2 V 2 O 7 in the framework of model and ab initio approaches [11,12] and experimental investigations of Lu 2 V 2 O 7 by NMR method [9]. At present there are no any experimental and theoretical data for other compounds in R 2 V 2 O 7 series.…”

“…Here, i) we analyzed the magnetic hyperfine interaction Hamiltonian leaning upon known orbital structure data and obtained the angular dependences of NMR spectrum under the external magnetic field for each V ion; ii) we could derive the information about hyperfine interaction values leaning upon the experimental data of NMR resonance frequencies [9]. Such calculations have been performed for Lu 2 V 2 O 7 [11,12]. We compared data from ab initio and model approaches and found a good agreement between them.…”