Browsing by Author "Swaroop, Ram"

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Design and development of a compact ion implanter and plasma diagnosis facility based on a 2.45 GHz microwave ion source
(American Institute of Physics Inc., 2021-05-25T00:00:00) Swaroop, Ram; Kumar, Narender; Rodrigues, G.; Kanjilal, D.; Banerjee, I.; Mahapatra, S.K.
A project on developing a 2.45 GHz microwave ion source based compact ion implanter and plasma diagnostic facility has been taken up by the Central University of Punjab, Bathinda. It consists of a double-wall ECR plasma cavity, a four-step ridge waveguide, an extraction system, and an experimental beam chamber. The mechanical design has been carried out in such a way that both types of experiments, plasma diagnosis and ion implantation, can be easily accommodated simultaneously and separately. To optimize microwave coupling to the ECR plasma cavity, a four-step ridge waveguide is designed. Microwave coupling simulation for the ECR plasma cavity has been performed at different power inputs using COMSOL Multiphysics. An enhanced electric field profile has been obtained at the center of the ECR plasma cavity with the help of a four-step ridge waveguide compared to the WR284 waveguide. The magnetic field distribution for two magnetic rings and the extraction system's focusing properties have been simulated using the computer simulation technique. A tunable axial magnetic field profile has been obtained with a two permanent magnetic ring arrangement. The dependency of the beam emittance and beam current on accelerating voltages up to 50 kV has been simulated with different ions. It shows that ion masses have a great impact on the beam emittance and output current. This facility has provision for in situ plasma diagnosis using a Langmuir probe and optical emission spectroscopy setups. This system will be used for ion implantation, surface patterning, and studies of basic plasma sciences. � 2021 Author(s).
Design and simulation of 2450 MHz microwave cavity for resonance and off-resonance plasma diagnosis in-situ plasma irradiation facility
(Institute of Physics, 2023-02-09T00:00:00) Swaroop, Ram; Kumar, Narender; Sabavath, Gopikishan; Choudhary, Virendra�Singh; Jewariya, Yogesh; Rodrigues, G.
The microwave plasma diagnosis in-situ irradiation system has been developed at the Central University of Punjab, Bathinda. The final design is achieved by a combination of analytical and simulation methods using CST and Comsol Multiphysics software. Simulations outcome reveals the electric field profile at the center of the microwave plasma chamber is strong and dense. A strong electric field profile inside the microwave cavity has been verified by the confinement of the plasma in the absence of an external magnetic field. The magnetic field profile for the 2450 MHz microwave facility is simulated and confirmed experimentally. Different RF powers and working gas pressures have been used with Langmuir probes to record the plasma signal. As a second stage, we studied the practicality of using a plasma cavity to treat materials with plasma for materials science experiment in plasma environment. This work shows the results of a thorough computational analysis of a microwave plasma source that has been tested in lab. � 2023 IOP Publishing Ltd and Sissa Medialab.
Effect of Nano-Filler on the Properties of Polymer Nanocomposite Films of PEO/PAN Complexed with NaPF 6
(Journal of Materials Science and Engineering B 5, 2016) Bhatt, Chandni; Swaroop, Ram; Arya, Anil; Sharma, A. L.
Free standing transparent PNC (Polymer nanocomposite) films based on PEO/PAN + NaPF 6 with different concentration (wt./wt.) filler of nano sized (TiO 2 ) is synthesized by using standard solution cast technique. HRXRD (High resolution X -ray diffraction) and FESEM (Field emission scanning electron microscopy) have been performed to see the structural and microstructural behavior of the PNC films. The microscopic interaction among polymer, salt and nano-ceramic filler has been analyzed by FTIR (Fourier transformed infra-red) spectroscopy. The reduction of ion pair formation in polymeric separator is clearly observed on addition of nano-filler in the polymer salt complex film. Electrical (ionic/electronic) conductivity has been estimated (~ 10 -4 S/cm) optimized PNC films concentration of nanofiller (15 Wt.%). The estimated value of electrical conductivity is well corroborated by FTIR study. Thermal analysis has been done with thermo gravimetry analysis to find out thermal stability of PNC films. Transport properties associated due to majority mobile carriers ions and only negligible participation from electrons was observed through transport number analysis. The band gap (i.e. direct as well as indirect) decreases on the addition of nano-filler observed from the optical analysis. The estimated result of the prepared PNC films are at par with desired value for the device application.
Electronic properties and mechanical strength of ?-phosphorene nano-ribbons
(American Institute of Physics Inc., 2016) Swaroop, Ram; Bhatia, Pradeep; Kumar, Ashok
We have performed first principles calculations to find out the effect of mechanical strain on the electronic properties of zig-zag edged nano ribbons of ?-phosphorene. It is found that electronic band-gap get opened-up to 2.61 eV by passivation of the edges of ribbons. Similarly, the mechanical strength is found to be increase from 1.75GPa to 2.65GPa on going from unpassivated nano ribbons to passivated ones along with the 2% increase in ultimate tensile strain. The band-gap value of passivated ribbon gets decreased to 0.43 eV on applying strain up to which the ribbon does not break. These tunable properties of ?-phospherene with passivation with H-Atom and applying mechanical strain offer its use in tunable nano electronics.
Electronic Properties and Mechanical Strength of β- Phosphorene Nano-ribbons
(AIP Publishing, 2016) Swaroop, Ram; Bhatia, Pradeep; Kumar, Ashok
We have performed first principles calculations to find out the effect of mechanical strain on the electronic of zig-zag edged nano ribbons of β-phosphorene. It is found that electronic get opened-up to 2.61 eV by of the edges of ribbons. Similarly, the mechanical strength is found to be increase from 1.75 GPa to 2.65 GPa on going from unpassivated nano ribbons to passivated ones along with the 2% increase in ultimate tensile strain. The value of passivated ribbon gets decreased to 0.43 eV on applying strain up to which the ribbon does not break. These tunable of β-phospherene with with H-atom and applying mechanical strain offer its use in tunable nano electronics.
Enhancing the electrochemical performance of TiO2 based material using microwave air plasma treatment with an ECR cavity
(Frontiers Media S.A., 2022-11-24T00:00:00) Swaroop, Ram; Rani, Pinki; Jamwal, Gaurav; Sabavath, Gopikishan; Kumar, Haldhar; Jewariya, Yogesh
The microwave-based plasma treatment facility at the Central University of Punjab Bathinda (CUPB) based on 2.45�GHz has been used to investigate the impact on the electrochemical performance of TiO2. This was accomplished by treating a number of pellets of TiO2 sample material with microwave plasma at an input power of 80�W. The palette is subjected to microwave plasma treatment at 30-, 60-, 80-, and 100-s intervals. Many such characterization methods, including UV-visible spectroscopy, FTIR, XRD, and FESEM, have been applied to the study of the impact of plasma treatment on other physical and chemical properties in the context of untreated pellets. In the 80-s plasma treatment, the FTIR study showed that the (O-Ti-O) vibration band at 500�900�cm?1 was wider than other bands. The UV results showed that an 80-s plasma treatment decreased the sample�s band gap by 37% and increased the amount of disordered, amorphous material in the sample that had not been treated. XRD studies show that a sample that was treated with plasma for 80�s has low crystallinity and a high disorder (amorphous) factor. The Nyquist plot showed that the electrochemical charge transfer resistance drops from 7 (not treated) to 4 after 80�s of plasma treatment. In a study of electrochemical performance, a sample that was treated with plasma for 80�s has a capacitance that is 35% higher than a sample that was not treated. Copyright � 2022 Swaroop, Rani, Jamwal, Sabavath, Kumar and Jewariya.
Fabrication of energy storage EDLC device based on self-synthesized TiO2 nanowire dispersed polymer nanocomposite films
(Springer Science and Business Media Deutschland GmbH, 2021-05-24T00:00:00) Devi, Chandni; Swaroop, Ram; Arya, Anil; Tanwar, Shweta; Sharma, A.L.; Kumar, Sandeep
In this work, a systematic study of titanium oxide (TiO2) nanowires incorporated polymer nanocomposite (PNC) films prepared by a standard solution cast technique is reported. The structural, morphological, dielectric, and electrochemical properties were investigated thoroughly. The polymer nanocomposite films demonstrated improved electrical and electrochemical properties as compared to polymer�salt complex film. The morphological and structural properties have been examined by the field emission scanning electron microscope, Fourier transform infrared spectroscopy, and X-ray diffraction. It is observed that the maximum ionic conductivity is of the order of 10�5 S cm?1 exhibited by 0.5 wt% nanowire added polymer nanocomposite film. The ion transference number was close to unity for optimized film and stability window of about ~ 5�V. The shift of loss tangent peak toward the high-frequency window with nanowire addition indicates a decrease of the relaxation time. The optimized TiO2 nanowire dispersed polymer nanocomposite film has been used to fabricate the electric double-layer capacitor cells. The fabricated cell demonstrates the specific capacitance of about 57.5 F/g (at 10�mV/s). The calculated energy density and power density are 1.38 Wh kg?1 and 0.709�kW�kg?1, respectively. The Coulombic efficiency is 97.7% up to the 500 cycles for the fabricated cell. The prepared polymer nanocomposite has the potential to use it as electrolyte cum separator for solid-state electric double-layer capacitor applications. � 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Shape-dependent electronic properties of blue phosphorene nano-flakes
(American Institute of Physics Inc., 2016) Bhatia, Pradeep; Swaroop, Ram; Kumar, Ashok
In recent year's considerable attention has been given to the first principles method for modifying and controlling electronic properties of nano-materials. We performed DFT-based calculations on the electronic properties of zigzag-edged nano-flakes of blue phosphorene with three possible shapes namely rectangular, triangular and hexagonal. We observed that HOMO-LUMO gap of zigzag phosphorene nano-flakes with different shapes is ?2.9 eV with H-passivations and ?0.7-1.2 eV in pristine cases. Electronic properties of blue phosphorene nano-flakes show the strong dependence on their shape. We observed that distributions of molecular orbitals were strongly affected by the different shapes. Zigzag edged considered nanostructures are non-magnetic and semiconducting in nature. The shape dependent electronic properties may find applications in tunable nano-electronics. ? 2016 Author(s).
Sodium-Ion-Conducting Polymer Nanocomposite Electrolyte of TiO 2 /PEO/PAN Complexed with NaPF 6
(AIP Publishing, 2016) Bhatt, Chandni; Swaroop, Ram; Sharma, Parul Kumar; Sharma, A. L.
A free standing transparent of state based on PEO/PAN+NaPF6 with different compositions of nano sized TiO2 in weight percent (x = 0, 1, 2, 5, 10, 15, 20) is synthesized by using standard cast technique. The homogeneous of above composition is examined by FESEM. The microscopic interaction among salt and nanoceramic filler has been analyzed by Fourier Transformed Infra-Red spectroscopy. The reduction of ion pair formation in polymeric separator is clearly observed on addition of nanofiller in the salt complex Electrical conductivity has been recorded of the prepared polymeric separator which is of the order of ∼10−4 Scm−1 after addition of nanofiller (15% wt/wt) which support the results. Electrochemical potential window has been observed of the order of ∼6V by the cyclic voltammetry results. The observed data of the prepared separator are at par with the desirable value for device applications
Structural and electrical properties of polymer nanocomposite films
(Springer Science and Business Media, LLC, 2017) Bhatt, Chandni; Swaroop, Ram; Sharma, Achchhe Lal
A free standing transparent film of solid state polymer electrolyte based on PEMA/PVC+NaPF6 with different compositions of nano sized TiO2 in weight percent (x = 0, 1, 2, 7, 10, 15, 20) is synthesized by using standard solution cast technique. The homogeneous surface of above polymer composition is examined by FESEM. The microscopic interaction among polymer, salt and nano-ceramic filler has been analyzed by Fourier Transformed Infra-Red (FTIR) spectroscopy. The reduction of ion pair formation in polymeric separator is clearly observed on addition of nano-filler in the polymer salt complex film. Electrical conductivity has been recorded of the prepared polymeric separator which is of the order of *1.5 × 10−5 Scm−1 10?5Scm?1 after addition of nano-filler (15 % wt/wt) which support the FTIR results. Electrochemical potential window has been observed of the order of ~6 V by the cyclic voltammetry results. The observed data of the prepared separator are at par with the desirable value for device application. - Springer International Publishing Switzerland - 2017.
Tunable electronic and dielectric properties of b-phosphorene nanoflakes for optoelectronic applications
(Royal Society of Chemistry, 2016) Bhatia, Pradeep; Swaroop, Ram; Kumar, Ashok
Since the discovery of α-phosphorene, it has drawn considerable attention because of its possible exfoliation as single layers. We report electronic and dielectric properties of β-phosphorene nanoflakes in various configurations using density functional theory. Armchair edge nanoflakes with various shapes are magnetic semiconductors while hydrogen passivated edge structures are non-magnetic semiconductors with energy gap in the range of ∼2.3–2.7 eV which is suitable for solar cell applications. Dielectric functions are highly anisotropic in the low energy range and become isotropic above 10 eV energy. The calculated static dielectric constant shows strong dependence on the shape and edge structure of the considered nanoflakes. We found significantly large plasmonic energy differences for nanoflakes with a particular shape but having different edge configurations. Our results demonstrate that electron energy loss spectroscopy may be useful to determine the various shapes and edge configurations of β-phosphorene nanoflakes. The tunable energy gap and dielectric response make the considered nanoflakes potential candidates for optoelectronic device applications.
Ultra-narrow blue phosphorene nanoribbons for tunable optoelectronics
(Royal Society of Chemistry, 2017) Swaroop, Ram; Ahluwalia, P. K.; Tankeshwar, K.; Kumar, Ashok
We report optoelectronic properties of ultra-narrow blue phosphorene nanoribbons (BPNRs) within the state-of-the-art density functional theory framework. The positive but small value of formation energy (?0.1 eV per atom) indicates the relative ease of the formation of BPNRs from their two-dimensional (2D) counterpart. The oscillatory behaviour of the electronic band gap of bare BPNRs with increasing width is attributed to the reconstruction of edge atoms. The static dielectric constant of BPNRs depends on the width and applied strain which in turn shows consistency with the Penn's model expression for semiconductors. Bare BPNRs exhibit both ? and ? + ? plasmonic structures while passivated ones possess only a ? + ? plasmonic structure that get blue-shifted (as large as ?3 eV) on increasing the width of the BPNRs which makes electron energy loss spectroscopy useful for identifying the width of BPNRs in real experimental situations. The mechanical strain induces a small red shift in, which is attributed to the modification in electronic band dispersion due to a different superposition of atomic orbitals on the application of applied strain. These tunable electronic and dielectric properties of BPNRs mean they may find applications in optoelectronic devices based on blue phosphorene. ? The Royal Society of Chemistry.