http://nopr.niscpr.res.in/handle/123456789/55921 2026-10-05T10:57:42Z http://nopr.niscpr.res.in/handle/123456789/58635 Title: Vacancy Induced Magnetism and Spin Filtering in 2D GaN Monolayer Authors: Yadav, Sandeep; Agrawal, B K; Yadav, P S Abstract: Exotic properties functionalized by Ga or N atom vacancies in two-dimensional GaN monolayer have been predicted for the first time. A detailed ab-initio study of the structural, electronic, magnetic and optical properties of a 2D–GaN monolayer containing Ga or N atom vacancies has been performed. In the present study, we make two refinements in the density functional theory. At first, long range dispersion interactions not discussed so far have been accounted for. Further, norm-conserving pseudopotentials and plane waves are employed in generalized gradient approximation in contrast to earlier workers who have used soft or ultra-soft pseudopotentials. One observes that the strength of induced magnetism depends not on the separation of Ga-vacancies but on the number of Ga atom vacancies. The magnetism induced by N-atom vacancies is either zero or quite small. Spin filtering has been observed in many configurations. A strong continuous absorption from the far infrared region to the deep visible region is seen in some systems. It may be useful for development of photo-emitting devices which will emit in various regions of energy spectrum including visible emission. The emission of 2D-GaN monolayer lying in deep ultraviolet region may be used for sterilization, water purification etc. Page(s): 795-802 2021-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/58634 Title: Yttrium Enhanced Glass-Forming Ability of Zr-Based Metallic Glasses Authors: Patel, Margi K; Upadhyay, Deepak; Lad, Kirit N; Pratap, Arun Abstract: Thermodynamic behavior of Zr56-xCo28Al16Yx (x = 0, 2, 7, 10 at. %) bulk metallic glass-forming alloys has been studied using an analytical approach where some of the key thermodynamic quantities such as ΔH, ΔS and ΔG have been estimated using a hyperbolic temperature dependence of specific heat difference ΔCp in the supercooled liquid region. The study is focused on understanding the effect of yttrium (Y) doping on the thermodynamics of the alloys in the supercooled region and on the glass-forming ability (GFA) of these alloys. The analytical approach has been found to give estimates of ΔG in a wide supercooled liquid region which is in excellent agreement with the experimental results. Estimated ΔG values are found to be minimum for Y concentration of 7% and 10% which is consistent with the observed high GFA for these compositions. Fundamental elemental properties such as atomic size, electronegativity, the heat of mixing have been found to play an important role in governing the thermodynamics of the alloys in the supercooled liquid region. Page(s): 803-810 2021-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/58633 Title: Advancement of High–k ZrO₂ for Potential Applications: A Review Authors: Chauhan, Vishnu; Gupta, Deepika; Upadhyay, Sonica; Ram, Jagjeevan; Kumar, Shalendra; Kumar, Rajesh Abstract: Versatile zirconium oxide as a ceramic has propelled a rapid development of science and technology for diverse applications. Among the class of ceramics, it holds a distinctive position due to its excellent physical, chemical and mechanical properties owing to its phase transformation. Zirconia is high k- dielectric, mechanical resistance and high radiation tolerance material. Although, this material replaces SiO2 due to its high dielectric constant so it can be employed to various memory device applications. It has essential implications in nuclear reactors, inert matrix fuel, nuclear waste systems, container for radioactive materials and designing of new materials owing to its high radiation tolerance property. Dentists proclaimed that zirconium oxide is “ceramic steel” where it has attracted prosthetic dentistry because of its strength and esthetics are admired. Addition of few percentages of stabilizers such as Y2O3, MgO and Ni etc. make it useful for specific applications. Zirconium oxide ceramic is indispensably used as an electrode and electrolyte in energy efficient solid state electrochemical devices (fuel cells) that generates electricity with good efficiency from natural gas and fuel cell plants and provides auxiliary power in vehicles. One of its important phase transformation mechanisms is being focused and extensively reviewed due to the effect of temperature variation and ion beam irradiation effect. The objective of current review is to present the knowledge of extensive properties, synthesis techniques and its various implications and guidelines for optical, medical, fuel cells, biological and electrical and memory devices and nuclear applications. The advantages of zirconia with respect to other oxide materials are also reviewed. Page(s): 811-826 2021-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/58632 Title: Flow of Dusty Non-Newtonian Fluid in a Vertical Channel in Presence of Inclined Magnetic Field Authors: Deb, Hridi Ranjan Abstract: A theoretical investigation of the influence of inclined magnetic field on the flow of non-Newtonian fluid with dust in a vertical channel has been considered. The non-Newtonian fluid is characterized by second-order fluid. The governing partial differential equations are obtained and solved analytically. The analytical expression for velocity field, temperature field, shearing stress flow flux at the channel are obtained. The potency of relevant parameters of the problem on velocity, shearing stress and flow flux of both dusty fluid and dust particles have been presented graphically. Page(s): 827-834 2021-12-01T00:00:00Z