MOHAMMED RASI U P
@sscollege.ac.in
ASSISTANT PROFESSOR & DEPARTMENT OF PHYSICS
SULLAMUSSALM SCIENCE COLLEGE, AREEKODE
RESEARCH INTERESTS
MAGNETISM. SPINTRONICS, THINFILMS, SILLENITES & MULTIFERROICS
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
M. S. Ravisankar and U. P. Mohammed Rasi
Springer Science and Business Media LLC
Shubhra Dash, A.V. Lukoyanov, Nancy, Durgamadhab Mishra, U.P. Mohammed Rasi, R.B. Gangineni, M. Vasundhara, and Ajit K. Patra
Elsevier BV
N.K. Shihab, Jitendra Nath Acharyya, U.P. Mohammed Rasi, R.B. Gangineni, G. Vijaya Prakash, and D. Narayana Rao
Elsevier BV
Abstract We report the optical field enhanced nonlinear absorption and photoluminescence of one-dimensional photonic crystal with BaTiO3 as a defect, fabricated via RF sputtering technique. The homogeneity of layer thickness is confirmed through field emission scanning electron microscopy (FESEM). The cavity resonance mode is obtained at 532 nm and the quality factor of the microcaviy is found to be 48. Open aperture Z-scan and spectral measurement of microcavity show enhancement in nonlinear absorption and photoluminescence of BaTiO3 at 532 nm and 355 nm, respectively due to the strong field confinement around the defect layer. The experiments are in good agreement with the transfer matrix method simulations.
N.K. Shihab, Jitendra Nath Acharyya, U.P. Mohammed Rasi, R.B. Gangineni, P. Anantha Lakshmi, G. Vijaya Prakash, and D. Narayana Rao
Elsevier BV
Abstract In this paper, an asymmetric 1-D photonic microcavity with BaTiO3 as defect has been fabricated using RF magnetron sputtering technique. Open aperture Z-scan shows enhancement in nonlinear absorption of BaTiO3 due to strong field confinement around the defect layer. We further report the switching behavior in nonlinear absorption from reverse saturable absorption to saturable absorption in response to the angle tuning of the sample. The transfer matrix simulation results further support the cavity defect in asymmetric photonic crystal confine the photon and thereby enhancing nonlinear optical phenomena.
U.P. Mohammed Rasi, N.K. Shihab, S. Angappane, and R.B. Gangineni
Elsevier BV
U. P. Mohammed Rasi, J. Arout Chelvane, S. Angappane, P. Magudapathy, S. Amirthapandian, and R. B. Gangineni
Springer Science and Business Media LLC
C S Chitra Lekha, Ajith S Kumar, S Vivek, U P Mohammed Rasi, K Venkata Saravanan, K Nandakumar, and Swapna S Nair
IOP Publishing
Harvesting energy from surrounding vibrations and developing self-powered portable devices for wireless and mobile electronics have recently become popular. Here the authors demonstrate the synthesis of piezoelectric energy harvesters based on nanotube arrays by a wet chemical route, which requires no sophisticated instruments. The energy harvester gives an output voltage of 400 mV. Harvesting energy from a sinusoidal magnetic field is another interesting phenomenon for which the authors fabricated a magnetoelectric energy harvester based on piezoelectric–magnetostrictive coaxial nanotube arrays. Piezoelectric K0.5Na0.5NbO3 (KNN) is fabricated as the shell and magnetostrictive CoFe2O4 (CFO) as the core of the composite coaxial nanotubes. The delivered voltages are as high as 300 mV at 500 Hz and at a weak ac magnetic field of 100 Oe. Further tailoring of the thickness of the piezoelectric and magnetic layers can enhance the output voltage by several orders. Easy, single-step wet chemical synthesis enhances the industrial upscaling potential of these nanotubes as energy harvesters. In view of the excellent properties reported here, the lead-free piezoelectric component (KNN) in this nanocomposite should be explored for eco-friendly piezoelectric as well as magnetoelectric power generators in nanoelectromechanical systems (NEMS).
P. Muhammed Razi, U. P. Mohammed Rasi, and R. B. Gangineni
AIP Publishing LLC
Influence of pressure on the dielectric properties of Poly (vinylidene fluoride) (PVDF) has been investigated. The pressure is varied by applying a 5 Ton and 10 Ton pressure during pellet preparation. The broad band dielectric spectroscopy is utilized for understanding the dielectric constant disparity with respect to frequency and temperature. XRD and Raman spectroscopy are utilized to comprehend the structural characteristics of PVDF with respect to pressure. A relaxor type ferroelectric behavior is observed from the complex dielectric constant versus temperature measured at different frequencies. Further, the deviations in the dielectric constant versus temperatures are discussed with respect to the structural evolutions of the PVDF.