X-ray standing wave determination of the lattice location of Er diffused into LiNbO3

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

“…1). Interestingly, similar off-center displacements are also observed for other trivalent rare-earth ions (e.g., Pr 3+ , Eu 3+ , Dy 3+ , Ho 3+ and Er 3+ ) replacing Li + in LiNbO 3 from the RBS technique [32][33][34] and X-ray standing wave (XSW) measurement [35]. These impurities are found not to occupy the exact Li + site, but to shift away from the center of oxygen octahedra by an amount Z (≈ −0.3 ∼ −0.45 Å).…”

Combined excitation emission spectroscopy of defects for site-selective probing of ferroelectric domain inversion in lithium niobate

“…We suspect that this effect is not caused by misaligned defect dipoles but by the averaging effect of defect dipoles and the positions of regular Nb and Li ions located on either side of the domain wall. This may lead to a difference in the offcenter position of the Er ion away from the value determined for the bulk material [7]. (2) The transition of the peak positions across the domain wall occurs within about 20 mm.…”

“…In lithium niobate (LiNbO 3 ) with its favorable nonlinear, and electro-optical properties, Er ions have been utilized in integrated optical lasers and optical amplifiers [1][2][3][4][5][6]. In this material, the trivalent ions occupy dominantly a Li site [7,8], and hence require charge compensation leading to complicated multisite spectra that are quite complicated in particular since the number and relative abundances of sites depend on the stoichiometry of the crystal, the thermal history, and the presence of other co-dopants. Nevertheless, a quite good (although not complete) understanding has been achieved [9][10][11][12][13].…”

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

“…The displacement of the Er 3+ from Li + site (Er Li center) obtained from X-ray standing way (XSW) is equal to ı ∼ = −0.46 Å [15] and measured by RBS/channeling technique ı ∼ = −0.2 Å [12]. Unfortunately, no experimental results for Er 3+ displacement from Nb 5+ site (Er Nb center) in LN crystal are available [3].…”