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Growth dynamics and spectroscopic characterization strategies of ‘L-proline' doped potassium hydrogen phthalate single crystal structural avenue. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.131647] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Rahman MK, Riscob B, Bhatt R, Bhaumik I, Ganesamoorthy S, Vijayan N, Bhagavannarayana G, Karnal AK, Nair L. Investigations on Crystalline Perfection, Raman Spectra and Optical Characteristics of Transition Metal (Ru) Co-Doped Mg:LiNbO 3 Single Crystals. ACS OMEGA 2021; 6:10807-10815. [PMID: 34056235 PMCID: PMC8153738 DOI: 10.1021/acsomega.1c00452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/26/2021] [Indexed: 06/12/2023]
Abstract
Congruent lithium niobate single crystals with a Ru:Mg co-dopant have been successfully grown using the Czochralski technique from the melt containing 0.02 mol % Ru with Mg of two varied concentrations (4.0 and 6.0 mol %). The effects of Ru and Mg co-doping on the crystalline quality were determined by high-resolution X-ray diffractometry, which confirmed that the crystalline quality is good and that the dopants are statistically distributed in the crystal. The Raman scattering analysis shows no change in the lattice vibration except a slight change in the peak width and intensity due to more asymmetry in the molecular charge, which leads to enhancement of the polarizability. The optical transmission spectra indicate that both the crystals have high optical transparency in the visible region, with a shift of the absorption edge toward shorter wavelengths, as compared to un-doped LN. The weak absorption band observed below 400 nm is attributed to Ru ions. The influence of co-doping in the electronic band gap energies is calculated by the Tauc relation. The refractive index is measured by using a prism coupler at two wavelengths (532 and 1064 nm). The calculated absorption coefficients and direct and indirect band gap energies for both the samples are found to be nearly the same within experimental error. A decrease in the birefringence is observed for the Ru:Mg(6 mol %) doped sample. The observed slight reduction in refractive indices with Ru:Mg co-doping is consistent with a rise in band gap energy, which is related to the change in absorption edge to the lower wavelength. The second harmonic generation (SHG) efficiency is measured by the Kurtz and Perry powder method, and a decrease in SHG efficiency for Ru:Mg(6 mol %) is observed.
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Affiliation(s)
| | - B. Riscob
- Institute
for Plasma Research, Bhat, Gandhinagar 382428, India
| | - Rajeev Bhatt
- Crystal
Growth and Instrumentation Section, Laser and Functional Materials
Division, Raja Ramanna Centre for Advanced
Technology, Indore 452013, India
- Homi
Bhabha National Institute, Training School
Complex, Anushakti Nagar, Mumbai 400094, India
| | - Indranil Bhaumik
- Crystal
Growth and Instrumentation Section, Laser and Functional Materials
Division, Raja Ramanna Centre for Advanced
Technology, Indore 452013, India
- Homi
Bhabha National Institute, Training School
Complex, Anushakti Nagar, Mumbai 400094, India
| | - Sarveswaran Ganesamoorthy
- Materials
Science Group, IGCAR, Kalpakkam 603102, India
- Homi
Bhabha National Institute, Training School
Complex, Anushakti Nagar, Mumbai 400094, India
| | - Narayanasamy Vijayan
- CSIR-National
Physical Laboratory, In-House BND Group, Dr. K. S. Krishnan Road, New Delhi 110012, India
| | | | - Ashwini Kumar Karnal
- Crystal
Growth and Instrumentation Section, Laser and Functional Materials
Division, Raja Ramanna Centre for Advanced
Technology, Indore 452013, India
- Homi
Bhabha National Institute, Training School
Complex, Anushakti Nagar, Mumbai 400094, India
| | - Lekha Nair
- Department
of Physics, Jamia Millia Islamia, New Delhi 110025, India
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Sun D, Kang X, Yu Q, Cui K, Qin X, Shi X, Cai H, Ohachi T, Sang Y, Liu H. Antisite defect elimination through Mg doping in stoichiometric lithium tantalate powder synthesizedviaa wet-chemical spray-drying method. J Appl Crystallogr 2015. [DOI: 10.1107/s1600576715002113] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
MgO-doped stoichiometric LiTaO3(MgO:SLT) is one of the most promising nonlinear materials. However, its industrial application is limited by the poor optical quality caused by the nonhomogeneous distribution of magnesium. Herein, an MgO:SLT polycrystalline powder was synthesized with a homogenous magnesium distribution by a wet-chemical spray-drying method. A comparative investigation of the coordination state of Ta ions in MgO:SLT powders synthesized by this method and by a conventional solid-state reaction method was performed by X-ray photoelectron spectroscopy. It is proved that the Ta–Li antisite was completely eliminated as a result of the homogeneous Mg doping in the SLT lattice using the wet-chemical spray-drying method. However, for MgO:LT powder produced by the solid-state reaction method, element analysis after acid treatment shows that some Mg ions did not enter the LT lattice after high-temperature calcination. Also, scanning electron microscopy and transmission electron microscopy energy dispersive spectroscopy verified that some MgO particles still exist in the as-synthesized MgO:LT powder. This synthesis method can be used for mass production of high-quality polycrystalline powders for doped crystal growth and some other doped oxide powder products with high melt point.
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