EPR study of low symmetry Er centers in congruent lithium niobate

Abstract

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)

Structures of Impurity Defects in Lithium Niobate and Tantalate Derived from Electron Paramagnetic and Electron Nuclear Double Resonance Data

“…Note that angular dependences of EPR spectra in xy-plane were not measured in these studies. Later measurements in all three principal planes [180][181][182][183] have shown that there is no line without angular dependence in the xy-plane, i.e., dominant Er 3+ center in cLN has C1 symmetry. This does not agree with statistically distributed vLi around Er 3+ Li [179].…”

Growth of Zr codoped Er:LiNbO3 and Er/Yb:LiNbO3 single crystal

“…The further reduction of lattice constants in Zr/Er/Yb-4/1/1 crystal is attributed to the large polarization ability of Yb 3 þ (50.7). From the view point of the crystallographic considerations, EPR results showed that the Er 3 þ -Er 3 þ pairs locate besides isolated Er 3 þ ions[25].The UC emission spectra of Er-1 and Zr/Er-4/1 under 980 nm excitation are shown inFig. 2A.…”