A5068940304- Photorefractive and Nonlinear Optics
- Ferroelectric and Piezoelectric Materials
- Solid State Laser Technologies
- Luminescence Properties of Advanced Materials
- Multiferroics and related materials
- Acoustic Wave Resonator Technologies
- Microwave Dielectric Ceramics Synthesis
- Glass properties and applications
- Photonic and Optical Devices
- Nonlinear Optical Materials Research
- Optical and Acousto-Optic Technologies
- Solid-state spectroscopy and crystallography
- Electronic and Structural Properties of Oxides
- Ga2O3 and related materials
- Advanced Fiber Laser Technologies
- Magnetic and transport properties of perovskites and related materials
- Advanced Photocatalysis Techniques
- ZnO doping and properties
- Advanced Condensed Matter Physics
- Crystal structures of chemical compounds
- Crystal Structures and Properties
- Supercapacitor Materials and Fabrication
- Terahertz technology and applications
- Ion-surface interactions and analysis
- Perovskite Materials and Applications
Raja Ramanna Centre for Advanced Technology
2015-2024
Homi Bhabha National Institute
2017-2024
Devi Ahilya Vishwavidyalaya
2014-2017
Sri Sivasubramaniya Nadar College of Engineering
2017
Anna University, Chennai
2014
Abstract Energy of the indirect and direct optical bandgap near‐stoichiometric lithium niobate (nSLN) crystals is evaluated by absorption measurement. The value (3.95 eV) consistent with earlier reports. However, energy 4.12 eV higher than previously reported experimental (3.68 eV). obtained here closer to recent theoretical estimated Thierfelder et al. [Phys. Status Solidi C 7 , 362 (2010)] in comparison predicted Ching Rev. B 50 1992 (1994)]. phonons involved allowed transitions have...
Electro-caloric effect in 0.45BaZr0.2Ti0.8O3-0.55Ba0.7Ca0.3TiO3 single crystal has been investigated and electro-caloric coefficient of ∼0.38 K mm/kV obtained near the tetragonal-to-cubic phase transition. The value is significantly higher than that for lead-free ferroelectric materials reported so far.
We present temperature-dependent refractive index along crystallographic b[010] and a direction perpendicular to (100)-plane for monoclinic phase (β) Ga2O3 single crystal grown by the optical floating zone technique. The experimental results are consistent with theoretical result of Litimein et al.1. Also, Sellmeier equation wavelengths in range 0.4–1.55 μm is formulated at different temperatures 30–175 °C. thermal coefficient above specified ∼10−5 /°C.
We report the manifestation of sunlight driven photocatalytic activity in nanostructured Gd substituted bismuth ferrite (BiFeO<sub>3</sub>) multiferroic photocatalyst.
A single crystal of lithium niobate is an important optoelectronic material. It can be grown from direct melt only in a deficient non-stoichiometric form as its stoichiometric composition exhibits incongruent melting. As result it contains number intrinsic point defects such Li-vacancies, Nb antisites, oxygen vacancies, well different types polarons and bipolarons. All these adversely influence optical ferroelectric properties pose deterrent to the effective use this Hence, controlling has...
Single crystals of YVO4 with different doping concentrations Yb (1.5, 3.0, 8.0, and 15.0 at. %) good crystalline quality (FWHM ∼43-55 arc sec rocking curve) were grown by the optical floating zone technique. Refractive index measurements carried out at four wavelengths as a function temperature. The show that concentration is increased, refractive varies marginally for ne whereas there significant change in value no. thermo-optic coefficient (dn/dT) was found to be positive ∼10-5/°C, which 1...
Congruent lithium niobate single crystals with a Ru:Mg co-dopant have been successfully grown using the Czochralski technique from melt containing 0.02 mol % Ru Mg of two varied concentrations (4.0 and 6.0 %). The effects co-doping on crystalline quality were determined by high-resolution X-ray diffractometry, which confirmed that is good dopants are statistically distributed in crystal. Raman scattering analysis shows no change lattice vibration except slight peak width intensity due to...
In this work three different growth methods have been used to grow β-Ga2O3 nanostructures. The nanostructures were characterized by Grazing Incident X-Ray Diffraction, Scanning Electron Microscopy, Transmission Microscopy and Photoluminescence Spectroscopy. spectra for all the samples of exhibit an UV blue emission band. relative intensity luminescence is strongly affected surface defects present on Our study shows that can be reliably determine quality Further opens up possibility using...
Single crystals of undoped and Co-doped β-Ga2O3 with different doping concentration have been grown using optical floating zone technique. The powder X-ray diffraction analysis shows no significant variation in lattice parameters on Co the crystal. absorption spectra a decrease edge Co-doping broad band range 950-1700 nmdue to transitions ions. that both crystal possess indirect bandgap gap energy decreasing increasing Co-doping. Further, Urbach has also estimated which is found increase...
Here we address the issue of growing single crystals Nd and Cr codoped YVO4, a promising self Q-switching laser material, in different oxygen partial pressures. Single 1.4% 0.7% were grown by optical floating zone (OFZ) technique. Our findings emphasize, as content growth atmosphere is increased, absorption band corresponding to 2A1→ 2B2 transition Cr5+, which participates self-Q-switching, improves significantly. Similarly, significant improvement observed present case comparison that...