Dr. R. Lavanya
@annaihajirawomenscollege.ac.in
Assistant Professor, Department of Physics
Annai Hajira Women's College
RESEARCH, TEACHING, or OTHER INTERESTS
Condensed Matter Physics, Multidisciplinary, Materials Science, Environmental Science
Scopus Publications
Scopus Publications
K. Iyakutti, V.J. Surya, R. Lavanya, V. Vasu, R. Rajeswarapalanichamy, and Y. Kawazoe
Elsevier BV
Lavanya Raveendran, Vasu Veerapandy, Brindha Mohan, Kanimozhi Balakrishnan, and Pushpalatha Selvarajan
IOP Publishing
of TiO 2 particles in polymer matrix with decreased agglomeration. The PC results show greater ef fi ciency of anionic dyes compared to cationic ones. to the repulsive interaction between the positively charged PANI and the cationic dye. EY shows higher decolorization ef fi ciency. The sample with fi ber morphology shows higher PC ef fi ciency due to the combined effect of PANI fi ber with higher aspect ratio and TiO 2 nanoparticles with high surface area. The observed red shift in the band gap of PANI fi ber composite the observed result. the of conditions on and photocatalytic behavior of the TiO 2 nanocomposites.
K. Iyakutti, R. Lavanya, R. Rajeswarapalanichamy, E. Mathan Kumar, and Y. Kawazoe
AIP Publishing
Using density functional theory, we have analyzed the ways and means of improving the minority carrier lifetime (MCL) by calculating the band structure dependent quantities contributing to the MCL. We have computationally modeled silicon doped with different elements like B, C, N, O, P, Ti, Fe, Ga, Ge, As, In, Sn, Sb, and Pt and looked at the effect of doping on MCL. In co-doping, the systems Si-B-Ga, Si-B-Ge, Si-B-2Ge, Si-B-Pt, Si-Ga-Ge, Si-Ga-2Ge, and Si-Ga-Pt are investigated. From our calculation, it is found that by doping and co-doping of Si with suitable elements having “s” and “p” electrons, there is a decrease in the recombination activity. The predicted effective minority carrier lifetime indicates the possibility of significant improvements. Based on the above studies, it is now maybe possible, with suitable choice of dopant and co-dopant material, to arrive at part of a standard production process for solar grade Si material.
M. Kanmani, R. Lavanya, D. Silambarasan, K. Iyakutti, V. Vasu, and Y. Kawazoe
Elsevier BV
Abstract In this first principles study, hydrogen storage capacity of armchair single-walled carbon nanotube (10, 10) functionalized with TiO 2 has been investigated. The functionalized TiO 2 molecules are found to be chemisorbed on CNT (10, 10) with the binding energy of 3.54 eV. The functionalized CNT binds up to six hydrogen molecules. The first hydrogen adsorption is dissociative with the binding energy of 1.51 eV and the further adsorbed hydrogen are weakly chemisorbed on the functionalized system with the elongated bond length of hydrogen. The storage capacity of functionalized SWCNT, desorption temperature and binding energy of hydrogen molecules are evaluated. The system exhibits a maximum storage capacity of 3.64 wt%. The band structure, density of states (DOS) and partial density of states (PDOS) are calculated for the functionalized and hydrogenated SWCNTs. DOS studies reveal that, functionalization and hydrogenation does not affect the metallic nature of CNT.
R. Lavanya, V.J. Surya, I. Lakshmi, K. Iyakutti, V. Vasu, H. Mizuseki, and Y. Kawazoe
Elsevier BV
R. Lavanya, V. J. Surya, K. Iyakutti, V. Vasu, and Y. Kawazoe
AIP Publishing LLC
The possibility of hydrogen storage in a hybrid system of Titanium dioxide (TiO2) and Tin dioxide (SnO2) functionalized C(10,10) armchair Single Walled Carbon Nanotube (SWCNT), i.e. SWCNT/TiO2/SnO2, is investigated using density functional, first principles study. The TiO2 and SnO2 molecules functionalized on the outer surface of SWCNT do not undergo any dimerization/clustering thus give excellent stability for the hybrid system SWCNT/TiO2/SnO2. The band structure and density of states (DOS) plots suggest that the functionalization transforms the nature (metallic → insulator) of the pristine system. The nominal values of H2 storage capacity and binding energies give much hope for using SWCNT/TiO2/SnO2 as a practical and reversible hydrogen storage medium (HSM).
Raveendran Lavanya, Gandhimathinathan Saroja, and Veerapandy Vasu
Trans Tech Publications, Ltd.
The thin films of WO3were prepared on cleaned microscopic glass substrates by the electron beam evaporation technique. The films were coated at room temperature using pure WO3pellets as source. The prepared films were further post heat treated at different temperatures (100°C to 350°C) for about 1hr in air. The optical properties of WO3 thin films were studied in detail. The increase in the density of the film as the annealing temperature increases have been confirmed by the transmittance spectra. The film annealed at 250°C shows a strong photoluminescence peak. The peak intensity is found to be less for all other temperature. The observed results were discussed in terms of crystalline nature of WO3.
R. Lavanya, K. Iyakutti, V. J. Surya, V. Vasu, and Y. Kawazoe
AIP
In this work, hydrogen storage in (10,10) armchair single walled carbon nanotube (SWCNT) functionalized with magnesium hydride (MgH2) has been investigated. As expected, due to light weight of MgH2, the system (SWCNT-MgH2) exhibits a storage capacity of 6.44 wt.%. The hydrogen adsorptions are molecular. The system is stable and thus H2 molecules can be desorbed without affecting the C – Mg attachment. Dimerization of MgH2 molecules has been observed. The binding energies confirm that the system can be used as a practical hydrogen storage medium.