Lattice site of Mg ion in LiNbO 3 crystal determined by Raman spectroscopy

Chapron

Journal of Applied Physics

et al. 2017

Raman measurements were investigated on Zr -doped lithium niobate LiNbO 3 crystals with different concentrations. Spectra were treated by fitting procedure and principal component analysis which both provide results consistent with each other. The concentration dependence of the frequency of the main low-frequency optical phonons gives an insight of site incorporation of Zr ions in the host lattice. The threshold concentration of about 2% is evidenced, confirming the interest of Zr doping as an alternative to Mg doping for the reduction of the optical damage in lithium niobate.

Section: Introductionmentioning

confidence: 79%

“…In previous studies we have shown that Raman spectroscopy (RS) can be a useful probe of dopant ion [15,16]. A shift of line position (optical phonon frequency) and/or linewidth (phonon damping) of some Raman lines can be thus related to incorporation of defects in the host lattice.…”

Section: Introductionmentioning

confidence: 99%

Zr doping on lithium niobate crystals: Raman spectroscopy and chemometrics

Chapron

Journal of Applied Physics

et al. 2017

Journal of Applied Physics

“…Therefore, contributions to the measured internal electric fields by PE induced long-range distortions are also likely and will be further investigated in Section III C. ions into the crystal leads to changes in parameters (intensity, position, and width) of existing peaks especially if the sites of involved oscillations are occupied by the dopants. 39,44,46 Furthermore, bands that would usually not be permitted for symmetry reasons appear and are ascribed to photorefraction 44,47,48 and defect induced symmetry breaking, 49 which explains the A(TO 4 ) band visible around 625 cm…”

Section: B Thickness Dependence Of Ferroelectric Switchingmentioning

confidence: 99%

Interface and thickness dependent domain switching and stability in Mg doped lithium niobate

Neumayer

Ivanov

Manzo

et al. 2015

Controlling ferroelectric switching in Mg doped lithium niobate (Mg:LN) is of fundamental importance for optical device and domain wall electronics applications that require precise domain patterns. Stable ferroelectric switching has been previously observed in undoped LN layers above proton exchanged (PE) phases that exhibit reduced polarization, whereas PE layers have been found to inhibit lateral domain growth. Here, Mg doping, which is known to significantly alter ferroelectric switching properties including coercive field and switching currents, is shown to inhibit domain nucleation and stability in Mg:LN above buried PE phases that allow for precise ferroelectric patterning via domain growth control. Furthermore, piezoresponse force microscopy (PFM) and switching spectroscopy PFM reveal that the voltage at which polarization switches from the "up" to the "down" state increases with increasing thickness in pure Mg:LN, whereas the voltage required for stable back switching to the original "up" state does not exhibit this thickness dependence. This behavior is consistent with the presence of an internal frozen defect field. The inhibition of domain nucleation above PE interfaces, observed in this study, is a phenomenon that occurs in Mg:LN but not in undoped samples and is mainly ascribed to a remaining frozen polarization in the PE phase that opposes polarization reversal. This reduced frozen depolarization field in the PE phase also influences the depolarization field of the Mg:LN layer above due to the presence of uncompensated polarization charge at the PE-Mg:LN boundary. These alterations in internal electric fields within the sample cause long-range lattice distortions in Mg:LN via electromechanical coupling, which were corroborated with complimentary Raman measurements. V C 2015 AIP Publishing LLC. [http://dx

“…The analysis of Mg 2+ ions localization in LN structure was made by many researchers and it has been shown that at MgO concentration less than threshold, Mg 2+ ions usually occupy positions of Li + -ions, preventing the appearance of antisite Nb Li ions [5][6][7][8][9]. However, when MgO concentration is above the threshold there are different models of Mg 2+ ions localization in LN crystal: 3.…”

Section: Introductionmentioning

confidence: 99%

“…However, when MgO concentration is above the threshold there are different models of Mg 2+ ions localization in LN crystal: 3. Mg 2+ ions occupy both Li + -ions and Nb Nb ions [9].…”

Section: Introductionmentioning

confidence: 99%

NMR Analysis of Mg Ion Localization in LiNbO₃Crystal

et al. 2010

The analysis of cation sublattices population in magnesium doped LiNbO 3 crystals is carried out. It is shown that volume concentration of lithium vacancies (V Li ) monotonously increases with increasing of MgO content in the crystal up to the threshold value. A series of LiNbO 3 crystals with various concentration of Mg 2+ were investigated by 7 Li and 93 Nb Nuclear Magnetic Resonance (NMR). It is concluded that the peculiarities of NMR spectra in Mg-doped LiNbO 3 crystals can be explained by the formation of defect complexes including Mg Li ions and V Li on the shortest distances between them.