EPR and optical studies of LiNbO3:Yb and LiNbO3:Yb, Pr single crystals

Lithium niobate crystals doped with ytterbium were studied using Electron Paramagnetic Resonance (EPR) and Electron Nuclear Double Resonance (ENDOR). The tremendous narrowing of EPR lines in nearly stoichiometric samples, when compared to those in congruent samples, allowed us to distinguish nine non‐equivalent centers, as well as line splitting caused by the hyperfine interaction of ytterbium electrons with the nuclear spins of two magnetic isotopes, 171Yb and 173Yb. Eight of the nine centers are described for the first time. It was found that three of the centers have axial C3 symmetry, and all others have the lowest C1 symmetry due to the presence of intrinsic defects and/or charge compensation defects in the near neighborhood of Yb3+. Characteristics of the g ‐tensor for all of the centers and hyperfine tensors for axial centers were determined. The ENDOR observations of Nb nuclei in the nearest neighborhood of Yb13+ gave direct evidence that the dominated axial Yb1 center has no charge compensator in its nearest surroundings (distant charge compensation mechanism). Both the EPR and ENDOR data for the main axial ytterbium center are explained by a supposition that Yb3+ ions substitute for Li+. Possible models for low‐symmetry centers are discussed. The obtained numerous spectroscopic parameters can be used as cornerstones for model calculations of Yb3+ centers in lithium niobate. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Section: The Epr Of Ybmentioning

confidence: 82%

Section: +mentioning

confidence: 99%

Electron paramagnetic resonance and electron‐nuclear double resonance of nonequivalent Yb³⁺ centers in stoichiometric lithium niobate

Malovichko

Bratus

Грачев

et al. 2008

“…From Tables 1 and 2, we can see that the calculation results are in quite good agreement with the experimental values. It should also be noted that 4 A for the 10 6 (MnO ) -coordination complex is obviously smaller than 4 A for the 4 6 (MnCl ) -coordination complex. For Mn 2+ ions in A-PCC crystals, we take 0.9804 N = in the calculation from the optical spectra of Mn-PCC for they have similar structures and the same type of ligand.…”

Section: The Local Structure Distortion For Mnmentioning

confidence: 91%

“…According to the Van Vleck approximation for the ( ) k G τ integral [24], we may obtain the following relations: / 0.119328 r r · Ò · Ò = is obtained from the radial wave function of the Mn 2+ ion in complexes [25]. 4 A is almost a constant for the 10 6 (MnO ) -coordination complex; its value can be determined from the optical absorption spectra of the Mn-PCC crystal [26]. In order to decrease the number of adjustable parameters and reflect the covalency effects, we use the Curie et al covalent theory and take an average covalence factor N to determine the optical parameters as follows [27]:…”

Section: The Local Structure Distortion For Mnmentioning

confidence: 99%

Determination of the local molecular structure of metal perchlorate complex from the electron paramagnetic resonance spectra for a substitution of Mn²⁺ ion: a complete energy matrices study

Zhao

Gao

et al. 2009

A simple theoretical method is introduced for studying the local molecular structure of the (MnO6)10– coordination complex. By diagonalizing the complete energy matrices of the electron–electron repulsion, the ligand field and the spin–orbit coupling for a d5 configuration ion in a trigonal ligand field, the local distortion structure of the (MnO6)10– coordination complex for Mn2+ ions in A–PCC:Mn2+ (PCC = {[(CH3)2N]2OPOPO[N(CH3)2]2}(ClO4)2, A = Mg, Zn) complex systems is investigated. Both the second‐order zero‐field splitting parameter b20 and the fourth‐order zero‐field splitting parameter b40 are taken simultaneously in the structural investigation. From electron paramagnetic resonance (EPR) calculations, the local structure parameters R = 2.18 Å, θ = 56.38° for Mn2+ ions in Mg–PCC:Mn2+ and R = 2.20 Å, θ = 56.52° for Mn2+ ions in Zn–PCC:Mn2+ complex systems are determined, respectively. It is found that the theoretical calculation results of the EPR spectra for Mn2+ ions in A–PCC:Mn2+ complex systems are in good agreement with the experimental values. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

“…Erbium doped lithium niobate (LN:Er) single crystal, beside LN:Yb [10], LN:Yb, Pr [11,12] and LN:Nd [13] is one more example of lithium niobate doped with rareearth ions, in which paramagnetic centers with the lowest C 1 symmetry were identified. This discovery is particularly important because of potential application of this crystal in optical devices.…”

Section: + Nb5+mentioning

confidence: 99%

EPR study of low symmetry Er centers in congruent lithium niobate

Bodziony

Kaczmarek

2008

Self Cite

Electron paramagnetic resonance study of congruent LiNbO3 single crystal weakly doped (0.1 wt%) with erbium is reported. The EPR lines originating both from the 167Er isotope with a hyperfine structure, as well as from the evenEr isotopes causing fine structure, are identified. Angular dependence of the EPR lines reveals the presence of several non‐equivalent centers. Deconvolution of the EPR line into several Lorentzian components in a plane perpendicular to the z‐axis (optical c‐axis) allowed us to show the Er3+ center with the lowest (C1) point group symmetry and estimate the values of g‐tensor. The obtained results confirmed the model of non‐ equivalent centers of the rare‐earth ions in lithium niobate having the lowest C1 symmetry due to the presence of intrinsic defects in the near‐neighborhood of RE3+. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)