<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

(SoNS) School of Natural Sciences

Physics

World University root node

Synthetic metals

A correlated study of linear optical absorption in tetracene and pentacene

Physical Review B

Photoinduced absorption in disubstituted polyacetylenes: Comparison of theory with experiments

We report on the growth of highly oriented Hf O2 thin films of monoclinic phase stabilized by 5% Co doping on (001) yttrium-stabilized zirconia (YSZ) using pulsed-laser deposition at 700 °C at an oxygen partial pressure of 10-4 Torr. On the other hand, pure Hf O2 of such quality did not grow on YSZ in wide range of growth parameters. Rutherford backscattering-ion channeling in this film showed a 24% minimum yield (χmin) indicating highly oriented film growth, while hardly any ion channeling was observed in the undoped sample. High-resolution transmission electron microscopy revealed a sharp interface, and no signature of Co clusters. Electron energy loss spectroscopy showed that Co is in the 2+ state. Attempts were also made to grow films on a (001) Si substrate, and the results showed a very low ion channeling yield (∼8%). © 2005 American Institute of Physics.

Fulltext

Applied Physics Letters

Growth of highly oriented Hf O2 thin films of monoclinic phase on yttrium-stabilized Zr O2 and Si substrates by pulsed-laser deposition

In this article we present the growth of hexagonal phase MgZnO on nonconventional substrates such as quartz and on sapphire for comparison of the device property. We are reporting the realization of MgZnO-based UV detector on quartz by the pulsed laser deposition technique. MgZnO films are characterized by x-ray diffraction, UV-visible spectroscopy, and Rutherford backscattering-channeling techniques. The morphology of the films is studied by atomic force microscopy. The metal-semiconductor-metal device was fabricated on the MgZnO film to study the device photoresponse under proper UV irradiation. © 2005 American Vacuum Society.

Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films

Realization of Mg (x=0.15)Zn (1-x=0.85)O -based metal-semiconductor-metal UV detector on quartz and sapphire

A brief overview is given of recent developments and fresh ideas at the intersection of PT-and/or CPT-symmetric quantum mechanics with supersymmetric quantum mechanics (SUSY QM). Within the framework of the resulting supersymmetric version of CPT-symmetric quantum mechanics we study the consequences of the assumption that the "charge" operator C is represented in a, differential-operator form of the second or higher order. Besides the freedom allowed by the Hermiticity constraint for the operator CP, encouraging results are obtained in the second-order case. In particular, the integrability of intertwining relations proves to match the closure of our nonlinear (viz., polynomial) SUSY algebra. In a particular illustration, our form of CPT-symmetric SUSY QM leads to a new class of non-Hermitian polynomial oscillators with real spectrum which turn out to be PT-asymmetric. © World Scientific Publishing Company.

International Journal of Modern Physics A

CPT-conserving Hamiltonians and their nonlinear supersymmetrization using differential charge-operators C

Known shape-invariant potentials for the constant-mass Schrödinger equation are taken as effective potentials in a position-dependent effective mass (PDEM) one. The corresponding shape-invariance condition turns out to be deformed. Its solvability imposes the form of both the deformed superpotential and the PDEM. A lot of new exactly solvable potentials associated with a PDEM background are generated in this way. A novel and important condition restricting the existence of bound states whenever the PDEM vanishes at an end point of the interval is identified. In some cases, the bound-state spectrum results from a smooth deformation of that of the conventional shape-invariant potential used in the construction. In others, one observes a generation or suppression of bound states, depending on the mass-parameter values. The corresponding wavefunctions are given in terms of some deformed classical orthogonal polynomials. © 2005 IOP Publishing Ltd.

Journal of Physics A: Mathematical and General

Deformed shape invariance and exactly solvable Hamiltonians with position-dependent effective mass

In a box of size L, a spatially antisymmetric square-well potential of a purely imaginary strength ig and size l &lt; L is interpreted as an initial element of the SUSY hierarchy of solvable Hamiltonians, the energies of which are all real for g &lt; g c (l). The first partner potential is constructed in closed form and discussed.

Czechoslovak Journal of Physics

PT -supersymmetric partner of a short-range square well

The occurrence of a noncollinear magnetic structure at a Mn monolayer grown epitaxially on Fe(100) is predicted theoretically, using spinor density-functional theory and observed experimentally, using x-ray magnetic circular dichroism (XMCD) and linear dichroism (XMLD) spectroscopies. The combined use of XMCD and XMLD at the Mn-absorption edge allows us to assess the existence of ferromagnetic and antiferromagnetic order at the interface and also to determine the moment orientations with element specificity. The experimental results thus obtained are in excellent agreement with the magnetic structure determined theoretically. {\textcopyright} 2005 The American Physical Society.

Physical Review Letters

Spin-flop ordering from frustrated ferro- and antiferromagnetic interactions: A combined theoretical and experimental study of a Mn/Fe(100) monolayer

The complex ion [Fe2III(μ-O)(phen) 4(H2O)2]4+ (1) (phen = 1,10-phenanthroline) and its hydrolytic derivatives [Fe2 III(μ-O)(phen)4(H2O)(OH)]3+ (1a) and [Fe2III(μ-O)(phen)4- (OH) 2]2+ (2a) coexist in rapid equilibria in the range pH 4.23-5.35 in the presence of excess phenanthroline (pKa1 = 3.71 ± 0.03, pKa2 = 5.28 ± 0.07). The solution reacts quantitatively with I- to produce [Fe(phen)3] 2+ and I2. Only 1 but none of its hydrolytic derivatives is kinetically active. Both inner and outer sphere pathways operate. The observed rate constants show second-order dependence on the concentration of iodide, while the dependence on [H+] is complex in nature. Added Cl- inhibits the formation of adduct with I- and thus retards the rate of inner sphere path, leading to a rate saturation at high [Cl-], where only the outer sphere mechanism is active. Kinetic data indicate that simultaneous presence of two l- in the vicinity of diiron core is necessary for the reduction of 1. © 2005 Wiley Periodicals, Inc.

Chemistry

International Journal of Chemical Kinetics

Kinetics and mechanism, of oxidation of iodide with a (μ-oxo)Diiron(III,III) complex in weakly acidic media

The title MnIV complex, [Mn(LH2)3] 4+ (LH2 = biguanide = H2NC(=NH)NHC(=NH)NH 2), an authentic two-electron oxidant, quantitatively oxidizes hydrazine (H2NNH2) to dinitrogen in the pH interval 2.00-3.50. The net four-electron oxidation of hydrazine is provided by two MnIV as established by stoichiometric studies. The overall reaction is composed of two parallel paths: [Mn(LH2)3]4+ + N2H5+ k1 → products [Mn(LH2)2(LH)]3+ + N2H 5+ k2 → products The values of k 1 and k2 (in M-1 S-1) are, respectively, (5.50 ± 0.6) · 10-3 and 11.4 ± 1.5 at 25.0° and I = 1.0M (NaNO3). The order k2 ≫ k1 is unusual as protonated oxidants are generally more reactive than their conjugate bases. The remarkably superior reactivity of the conjugate base of the oxidant in oxidizing N2H5+ may be at least in part due to an overall positive-charge reduction in [Mn(LH 2)2(LH)]3+ as compared to [Mn(LH 2)3]4+ that favors reaction with positively charged N2H5+, and more plausibly, a change in the mechanism is responsible for this result as not k1 but k 2 is substantially lowered in D2O media indicating that proton motion is coupled with electron transfer in the k2 path. The rate-determining step appears to be a one-electron transfer from N 2H5+ to MnIV. © 2005 Verlag Helvetica Chimica Acta AG.