Journal of Theoretical and Applied Physics (JTAP) Electrodeposition of cobalt oxide thin films for potential applications Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Electrodeposition of cobalt oxide thin films for potential applications 10.57647/J.JTAP.2023.1702.25 EN Sandra Augustine Department of Physics and Industrial Physics, Nnamdi Azikiwe University, Awka, Nigeria Azubike Josiah Ekpunobi Department of Physics and Industrial Physics, Nnamdi Azikiwe University, Awka, Nigeria 0000-0002-5111-7298 Diemiruaye Mimi Jeroh Department of Physics and Industrial Physics, Nnamdi Azikiwe University, Awka, Nigeria 0000-0002-1622-0337 Journal Article 2023 11 17 Cobalt oxide thin films at varied molar concentrations were prepared by electrodeposition technique. Ultraviolet-Visible (UV/VIS) analysis conducted on the grown films revealed blue shift in the absorption edge at increased molar concentrations, which is a consequence of band gap widening. The band gap values (3.65 eV to 3.85 eV) in this research are greater than the value (2.4 eV) for the bulk phase of cobalt oxide. This increase in band gap can be likened to higher concentration effect and quantum-size phenomenon. Scanning Electron Microscopy (SEM) analysis indicated a porous nature for the material, suggesting its ability in absorbing ultraviolet (UV) radiation, thus confirming its use as an absorber material for solar cells fabrication. Energy Dispersive X-ray (EDX) study confirmed the growth of cobalt oxide. X-ray diffraction (XRD) analysis confirms the crystalline nature of the films with grain sizes within the range of 0.7 nm to 1 nm for varied molar concentrations. Electrical studies reveal a linear relationship of resistivity values with molar concentrations, while the conductivity values reveal inverse relationship with molar concentration.

Journal of Theoretical and Applied Physics (JTAP) Excitation of R- and L-waves by laser propagation through over-dense magnetized plasma and their verification Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Excitation of R- and L-waves by laser propagation through over-dense magnetized plasma and their verification 10.57647/J.JTAP.2023.1702.24 EN Gaurav Kumar Department of Physics, Indian Institute of Technology, New Delhi, India Hitendra K. Malik Plasma Science and Technology Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India 0000-0002-9432-8140 Journal Article 2023 11 17 Laser-plasma interaction is a fascinating subject in view of its various applications in wave generation, particle acceleration, radiation generation, etc. The laser beam gets reflected at the vacuum-plasma interface if the plasma density is equal or larger than the critical density. However, in the presence of strong magnetic field in the order of kilo Tesla, the beam can travel some distance through over-dense plasma. Here E×B heating and pondermotive force play role for the laser beams to propagate through the over-dense plasma. In the present article, taking the external magnetic field along the propagation direction of the laser beam we have observed the R- and L- waves to be excited. The applied magnetic field is chosen in such way that the laser frequency 𝜔𝑙 falls between the electron cyclotron frequency 𝜔𝑐𝑒 and ion cyclotron frequency 𝜔𝑐𝑖. Under this situation, it generates only an R-wave. If the laser frequency is considered to be less than the ion cyclotron frequency ( 𝜔𝑙𝑎𝑠𝑒𝑟<𝜔𝑐𝑖) then an L-wave is additionally generated. In both the cases, an electrostatic disturbance is also formed with different but significant electric field amplitudes. We simulate these R- and L-waves in 1-D by using Particle-in-Cell (PIC) simulation using the EPOCH-4.17.10. Specifically, the electric and magnetic fields are studied that are associated with these waves, and the waves are verified based on the dispersion relation and the polarization studies.

Journal of Theoretical and Applied Physics (JTAP) Enhancement of Seebeck coefficient with full spin polarization of CsMgN2 Thin Films: A DFT Study Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Enhancement of Seebeck coefficient with full spin polarization of CsMgN2 Thin Films: A DFT Study 10.57647/J.JTAP.2023.1702.23 EN Rohangiz Ashtari Faregh Department of Physics, Hamedan Branch, Islamic Azad University, Hamedan, Iran Arash Boochani Department o Physics, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran 0000-0002-2383-4169 Seyedeh Razyeh Masharian Department of Physics, Hamedan Branch, Islamic Azad University, Hamedan, Iran Journal Article 2023 11 17 Structural, electronic, and thermoelectric properties of the CsMgN2 compound with its thin film films of Cs-Mg and Mg-N terminations have been studied in a First-Principles study. The total energy changes (E-V) versus the unit cell volume of bulk show better stability in the ferromagnetic than the non-magnetic phase. The E-V diagrams of film Cs-Mg and Mg-N terminations have the ground state points at the ferromagnetic phase. The derivative bulk modulus of Cs-Mg termination is like the bulk phase, which refers to the ionic bonds between atoms. The magnetic moment of the bulk and two mentioned terminations have the integers of 3µB, 10 µB, and 13 µB, respectively. The DOS and bandstructure diagrams by the mBJ and GGA approximations confirm the half-metallic behavior of the bulk and the mentioned terminations. The energy gaps of their semiconductor phase are 1.40eV, 0.64eV, and 0.20eV, for the bulk, Cs-Mg, and Mg-N terminations, respectively. The Seebeck coefficient of Cs-Mg termination in 200K temperature is much higher than the bulk case. The merit figure of coefficient (ZT) shows that bulk and mentioned terminations have high thermoelectric quality at up spin.

Journal of Theoretical and Applied Physics (JTAP) Dopant and milling time effect on impedance and electrical properties of perovskite ceramics Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Dopant and milling time effect on impedance and electrical properties of perovskite ceramics 10.57647/J.JTAP.2023.1702.22 EN Shristi Chaudhary Chandigarh University Gharuan Mohali Punjab, India 0000000188642830 Mikanshi Chaudhary Chandigarh University Gharuan Mohali Punjab, India Sheela Devi Chandigarh University Gharuan Mohali Punjab, India 0000000291830290 Shilpi Jindal Chandigarh University Gharuan Mohali Punjab, India 0000000172956739 Journal Article 2023 11 17 Tungsten doped Barium Titanate (BT) with composition BaW0.05Ti0.95O3 (BWT) were prepared by using ball milling technique for different hours (10h, 20h and 30h). In the present paper, the microstructural, dielectric and impedance studies are discussed. The microstructural studies using XRD data reveals the formation of single phased tetragonal structure and perovskite structure. The dielectric properties of BT nanoceramics were significantly enhanced by the partial replacement of W (at B site) showing the diffuse phase transition at 80°C. Dielectric loss rises as the temperature rises. There is increase in charge carrier mobility which results in increased polarization and significant dielectric loss. Additionally, compared to the un-milled BWT ceramic sample, the 30h milled had superior dielectric characteristics with high dielectric constant and reduced loss. The nature of the phase transition was confirmed by the Curie-Weiss law and the ferroelectric analysis was carried by well-established P-E loops. The impedance studies were carried out by plotting Nyquist plots. The ac conductivity plot follows Arrhenius relation and the calculated activation energy confirms the negative temperature coefficient of resistance (NTCR) behavior of the material.

Journal of Theoretical and Applied Physics (JTAP) Numerical investigations of electron-self-injection in different shaped bubbles in wakefield acceleration Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Numerical investigations of electron-self-injection in different shaped bubbles in wakefield acceleration 10.57647/J.JTAP.2023.1702.21 EN Sonu Kumar Department of Physics, Indian Institute of Technology Delhi, New Delhi - 110016, India Dhananjay K Singh Department of Physics, PKRM College, Dhanbad - 826004, Jharkhand, India Hitendra K. Malik Plasma Science and Technology Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India 0000-0002-9432-8140 Journal Article 2023 11 17 Electron-self-injection in bubble wakefield acceleration is the new concept for acceleration of electrons inside bubble. In this technique, self-injected plasma electrons have been used for acceleration whose advantage is that there is no need of external source of electrons. In our case, we have carried out numerical investigations of self-injected plasma electrons in different shaped bubbles such as spherical, longitudinal ellipsoid and transverse ellipsoid bubble. For these numerical investigations, by carrying out relativistic Hamiltonian analysis of plasma electrons, we have used 4th order Runge-Kutta (RK) method by employing MATLAB ode45, a nonstiff differential equations solver. We have discussed different parameters such as impact parameter, radius of bubble, bubble velocity for their effect on the formation of bubbles with different shapes and self-injection of the electrons.

Journal of Theoretical and Applied Physics (JTAP) Structural and electronic properties of Li_n, B_n, N_n and O_n (n=1-4) clustering on graphene: Density functional theory calculations with dispersive forces correction Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Structural and electronic properties of Li_n, B_n, N_n and O_n (n=1-4) clustering on graphene: Density functional theory calculations with dispersive forces correction 10.57647/J.JTAP.2023.1702.20 EN Malika Gallouze Department of Theoretical Physics, Physics Faculty, University of Science and Technologie Houari Boumediene 0000-0003-1745-5514 Mahrez Drir Department of Theoretical Physics, Physics Faculty, University of Science and Technologie Houari Boumediene Abdelhafid Kellou Department of Theoretical Physics, Physics Faculty, University of Science and Technologie Houari Boumediene Journal Article 2023 11 17 We have performed density functional theory calculations to study the adsorption of Li, B, N, and O clusters on graphene to clarify the interaction of these atoms with a graphene sheet. The stable structure, the adsorption energy, and the density of states (DOS) of atom-graphene systems are calculated. The obtained results of the structural, adsorption and interaction energies show that light atoms on graphene show physisorption/chemisorption mechanisms with and without clusteringoccurrence. More interestingly, the formation of diatomic molecules is noticed. For example, Li atoms prefer to be physisorbed where as B atoms prefer the clustering configuration on the graphene sheet. For N and O atoms, the results show that the formation of molecules on a graphene sheet is preferred. The densities of states calculations have been performed to study the electronic properties of the studied systems. The results show that electronic structures are affected by the increasing concentration and the nature of adsorbed light atoms.

Journal of Theoretical and Applied Physics (JTAP) Investigation of plasma-activated water effects on preservation and physicochemical properties of Petroselinum crispum and Lepidium sativum Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Investigation of plasma-activated water effects on preservation and physicochemical properties of Petroselinum crispum and Lepidium sativum 10.57647/J.JTAP.2023.1702.19 EN Meysam Nikpour Plasma Technology Research Core, Faculty of Science, University of Mazandaran, Babolsar, Iran 0000-0002-0046-4775 Farshad Sohbatzadeh Department of Atomic and Molecular Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Mazandaran 47416‑95447, Iran Ehsan Nazifi Department of Atomic and Molecular Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Mazandaran 47416‑95447, Iran Saeed Mirzanejhad Department of Atomic and Molecular Physics, Science Faculty, University of Mazandaran, Babolsar, Iran Journal Article 2023 11 17 The present study aims at highlighting plasma, plasma-activated water (PAW) in particular, as a means of alternative, an innovative and unique method for its application in different aspects of food and vegetable processing and preservation. To investigate the effect of PAW on nutrient retention in vegetables, an experimental set was used to produce PAW that processes deionized water (DI). The concentrations of reactive species in PAW were calculated to compare their effect on nutrient retention. Then, the vegetables were washed with DI and PAW for 20 minutes. The samples were stored at 4 ° C for 14 days. Immediately after washing and on the seventh and fourteenth days, nutrient content levels were measured. The results showed that using PAW causes the nutrients to remain in the vegetables for a longer time. We show that nutrient persistence in vegetables depends on the concentration and the type of reactive species in PAW.

Journal of Theoretical and Applied Physics (JTAP) Magnetic susceptibility and Magnetocaloric effect of Frost-Musulin potential subjected to Magnetic and Aharonov-Bohm (Flux) fields for CO and NO diatomic molecules Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Magnetic susceptibility and Magnetocaloric effect of Frost-Musulin potential subjected to Magnetic and Aharonov-Bohm (Flux) fields for CO and NO diatomic molecules 10.57647/J.JTAP.2023.1702.18 EN Eddy Sunday William Department of Physics, Faculty of Physical sciences, University of Calabar, Calabar, Nigeria 0000-0002-5247-5281 Stanley C. Onye Department of Computer Science, Faculty of Computing, Air Force Institute of Technology, Kaduna, Nigeria Akpan Ndem Ikot Theoretical Physics Group, Department of Physics, University of Uyo, Uyo, Nigeria 0000-0002-1078-262X Arthur N. Nwachukwu Department of Physics, Alex Ekwueme Federal University Ndufu-Alike, Ebonyi State, Nigeria Etido P Inyang Department of Physics, National Open University of Nigeria, Jabi, Abuja, Nigeria 0000-0002-5031-3297 Ituen B. Okon Department of Physics, University of Uyo, Uyo, Nigeria Ita Okon Akpan Department of Physics, Faculty of Physical sciences, University of Calabar, Calabar, Nigeria Benedict I. Ita Department of Pure and Applied Chemistry, University of Calabar, Calabar, Nigeria Journal Article 2023 11 17 In this paper, we perform a nonrelativistic study of Frost-Musulin potential (FMP) impacted by the external magnetic and AB flux fields for the CO and NO diatomic molecules using the Nikiforov-Uvarov method with the Greene-Aldrich approximation to the centrifugal barrier. The numerical computation of the proposed potential reveals that the combined impact of the magnetic and AB flux fields completely removes the degeneracy of the energy spectra and controls the behavior of the magnetocaloric effect (MCE) by acting as a regulating factor to cool or heat the MCE. Also, the thermomagnetic plots obtained for the analyzed dimer molecules agreed perfectly with previous work. This research has the potential to be applied in molecular physics and MCE studies for a variety of molecules.

Journal of Theoretical and Applied Physics (JTAP) Theoretical study of ISB conduction optical absorption and impurity binding energy associated with lowest excited states in QW with a new modulated potential Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Theoretical study of ISB conduction optical absorption and impurity binding energy associated with lowest excited states in QW with a new modulated potential 10.57647/J.JTAP.2023.1702.17 EN Redouane En-nadir Le Mans Université, Faculty of sciences, University of Sidi Mohamed Ben Abdullah, Fez, Morocco 0000-0002-5064-0028 Haddou El-ghazi Le Mans Université, Faculty of sciences, University of Sidi Mohamed Ben Abdullah, Fez, Morocco ENSAM, Hassan-II University, Casablanca, Morocco 0000-0002-2139-2360 Journal Article 2023 11 17 This paper provides a theoretical investigation of the ground and first excited-states donor impurity binding energy and the linear and nonlinear optical absorption coefficients in quantum well with novel modulated potential called Redouane-Haddou potential (RHP). Within the effective-mass theory, the Schrödinger equation has been calculated numerically using the finite element method. The analytical expressions of the optical absorption coefficients are obtained within compact density matrix theory. Our results reveal that the A-parameter has a significant influence on the confinement profile and electron states, therefore, the binding energy as well as the optical properties of the investigated system. It increases the binding energy and redshift (blueshift) associated with drop (improvement) of the linear and nonlinear optical absorption coefficients related to 2p→1s,2p→2s, and 3s→2p transitions. Moreover, it is noticed that with an appropriate choice of the A-parameter and structure dimension, the optical response of the investigated system can be tailored in a controllable manner.

Journal of Theoretical and Applied Physics (JTAP) Effect of collisions, ionisation and non-extensivity on sheath formation in an electronegative warm plasma under electron emission from the wall Volume 17 (2023) JTAP Issue 2, May & June 2023 2023 11 17 Effect of collisions, ionisation and non-extensivity on sheath formation in an electronegative warm plasma under electron emission from the wall 10.57647/J.JTAP.2023.1702.16 EN Yetendra Prasad Jha Plasma Science and Technology Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India Mayank Kumar Department of Mechanical Engineering, Indian Institute of Technology Delhi, New Delhi, India Hitendra K. Malik Plasma Science and Technology Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India 0000-0002-9432-8140 Journal Article 2023 11 17 The effect of collisions, ionisation and non-extensivity is studied numerically in an electronegative warm plasma associated with electron emission from the wall. Electrostatic potential, space charge density, net negative charge density and emitted electron beam density are plotted with the normalised distance to see the effects of aforesaid parameters The negative ion is described with fluid equations to see it’s effect of the mass ratio (negative ion to positive ion) on emitted electron beam density inside the sheath. The three types of electronegative plasma taken are CF_4, O_2 and C_60. The emitted beam electron density is more in number at the wall for higher collisional and ionisation case and less in higher mass ratio. For super-extensive case the emitted beam electrons is lesser than compared to the Boltzmann distributed electrons. The sheath thickness is found to be more in higher mass ratio, emitted beam electrons and super -extensive case while for higher collisional and ionisation case the sheath thickness is less.