Studies of the EPR g factors and the local structure for the trigonal Nd3+ center in LiNbO3:Nd3+ crystal

Processing and Properties of Eu3+:LiTaO3 TransparentGlass–Ceramic Nanocomposites

“…In perovskite‐type LiTaO 3 crystals, Li + and Ta 5+ occupy octahedral sites with C 3 or nearly C 3v point symmetry. The Eu 3+ ion is entering into the crystal (LiTaO 3 ) and it prefers to replace Li + over Ta 5+ site‐forming [REO 6 ] 9− octahedron 19–21 because of the closeness of their ionic radii (Eu 3+ =0.95 Å, Li + =0.74 Å and Ta 5+ =0.64 Å). However, there still exists a slight difference in the ionic radii between the dopant Eu 3+ and the host Li + ions and, consequently, a distorted [EuO 6 ] 9− octahedron is formed with the Eu 3+ ion facing an off‐center displacement from the C 3 axis in the oxygen octahedron 22,23 .…”

The relationship between the g-shift and the local structure for the axial impurity centers in the doped LiNbO3 crystals

“…(6) and those obtained from PM theory [10] and, especially, with RBS experiment [12] in the case of LiNbO 3 :Nd single crystal.…”

“…Choh et al [9] report SH parameters of new Nd 3+ (and Er 3+ ) centers in lithium niobate single crystal. The EPR g-factor and the local structure for the trigonal Nd 3+ center in LiNbO 3 :Nd single crys- tal are investigated, too [10]. Wu and Dong used the perturbation theory of the EPR g factors (g ⊥ and g || ) and established an off-center displacement Nd 3+ ions from Li + site [10].…”

“…The values of the displacements ı obtained from other methods are revealed in Table 1, too. Wu and Dong (PM method) estimated an off-center displacement as equal to −0.28 Å [10]. The displacement obtained from Rutherford backscattering spectrometry (RBS) experiment is equal to −0.40 Å [12].…”

Nanostructured LiTaO3 and KNbO3 Ferroelectric Transparent Glass-Ceramics for Applications in Optoelectronics

“…10 (Wu & Zheng, 2002, Wu & Dong, 2005, Chang et al, 1993 due to the closeness of their ionic radii (Eu 3+ = 0.95 Å, Li + =0.74 Å and Ta 5+ = 0.64 Å). The local field asymmetry defining factor such as relative intensity ratio of I ED to I MD of Eu 3+ doped glass and nano glass-ceramics has been estimated from their photoluminescence spectra and it was found that the asymmetric ratio of all samples was greater than unity, which implies that the Eu 3+ ions take non-centrosymmetric sites.…”