Investigations on Crystalline Perfection, Raman Spectra and Optical Characteristics of Transition Metal (Ru) Co-Doped Mg:LiNbO 3 Single Crystals.

Autor:	Rahman MKR; Department of Physics, Jamia Millia Islamia, New Delhi 110025, India., Riscob B; Institute for Plasma Research, Bhat, Gandhinagar 382428, India., Bhatt R; 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., Bhaumik I; 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., Ganesamoorthy S; Materials Science Group, IGCAR, Kalpakkam 603102, India.; Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India., Vijayan N; CSIR-National Physical Laboratory, In-House BND Group, Dr. K. S. Krishnan Road, New Delhi 110012, India., Bhagavannarayana G; VSM Group of Institutions, Ramachandrapuram, E.G. (Dt.), Andhra Pradesh 533255, India., Karnal AK; 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., Nair L; Department of Physics, Jamia Millia Islamia, New Delhi 110025, India.
Jazyk:	angličtina
Zdroj:	ACS omega [ACS Omega] 2021 Apr 15; Vol. 6 (16), pp. 10807-10815. Date of Electronic Publication: 2021 Apr 15 (Print Publication: 2021).
DOI:	10.1021/acsomega.1c00452
Abstrakt:	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. Competing Interests: The authors declare no competing financial interest. (© 2021 The Authors. Published byAmerican Chemical Society.)
Databáze:	MEDLINE
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