Jawaharlal Nehru Centre for Advanced Scientific Research — Publications | RDL Network

Home Publications Thesis Researchers Datasets Faculties

Publications

2,089 publications from this institution

Surfactant-promoted formation of fractal and dendritic nanostructures of gold and silver at the organic–aqueous interface

The effect of surfactants such as tetraoctylammoniumbromide (TOAB) and cetyltrimethylammoniumbromide (CTAB) on the type of nanostructures formed when gold ions present in the organic phase are reduced at the interface by hydrazine in the aqueous phase has been investigated. Extended fractal structures are formed at the liquid–liquid interface, the fractal structures themselves comprising cauliflower type units formed by gold nanorods. Accordingly, the nanostructures exhibit transverse and longitudinal plasmon adsorption bands in the 550 and 800 nm regions, respectively. Dendritic structures of silver are formed at the interface when Ag ions are reduced similarly in the presence of surfactants. The nanostructures consist of nanoparticles or nanorods with five-fold symmetry.

Ved Varun Agrawal, Giridhar U. Kulkarni, Cnr Rao 2007Article

Determination of acidities of zeolites by photoacoustic spectroscopy

Photoacoustic spectroscopy is found to be a useful technique for determining the acidity of zeolites. The acidity so determined correlates well with temperature programmed desorption studies of ammonia and product distribution.

Thayumanasamy Somasundaram, P. Ganguly, Cnr Rao 1987Article

A core-level photoemission spectroscopic study of the electron-doped superconductor, Nd2-xCexCuO4-δ

A photoemission study of superconducting Nd1.85Ce0.15CuO4-δ shows that Ce in the cuprate is essentially in the 4+ state. While the electron donated by Ce does not appear to affect the Cu 3d band, we still find evidence for the presence of considerable Cu1+ - related configurations due to covalency effects. A role for oxygen holes and Cu1+ species is indicated just as in other cuprate superconductors.

M.K. Rajumon, D. D. Sarma, R. Vijayaraghavan et al. 1989Article

Structure and Superconducting Properties of Ga-substituted YBa2Cu3O7−δ and YBaSrCu3O7−δ Systems

No abstract is provided for this article.

R. Nagarajan, Cnr Rao 1995Chapter in a book

ChemInform Abstract: Holes in the Oxygen (2p) Valence Bands and the Concomitant Formation of Peroxide‐Like Species in Metal Oxides: Their Role in Metallicity and Superconductivity.

In an effort to explore for the presence of O(2p) valence band holes forming peroxide‐like species, several oxide systems (BaO 2 , PbO, BaPbO 3 , SrPbO 3 , BaBiO 3 , BaBiPbO 3 , La 2 NiO 4+δ ) have been investigated by photoelectron spectroscopy.

Cnr Rao, P. Ganguly, M. S. Hegde et al. 1988Article

Organically-templated Kagomé compounds containing two transition metal ions

Kagomé compounds containing two transition metal ions, CoII and NiII, in different proportions have been synthesized, and their magnetic properties have been found to exhibit interesting differences.

C. M. Nagaraja, J. N. Behera, Tapas Kumar Maji et al. 2010Article

Nanorods and nanofilms of ZnO generated at the liquid–liquid interface

Reaction between zinc cupferron and alkali at the organic–aqueous interface has been investigated in detail. In the presence of an organic amine, this reaction yields ZnO nanorods, the morphology depending on the concentration of reactants. In the absence of the amine, ultrathin films of ZnO are produced. Amazingly, both the nanorods and thin films are single crystalline in nature, even though the synthesis is carried out at room-temperature. Single-crystalline, substrate-free ultrathin films of ZnO, is indeed an extraordinary feature of synthesis at the liquid–liquid interface. Photoluminescence spectra show defect-related bands besides that due to band edge emission. The nanostructures exhibit ferromagnetism due to surface defects.

S. Manjunatha, Leela S. Panchakarla, Kanishka Biswas et al. 2010Article

Solvation (C.T.T.S.) spectra of the iodide ion. Role of hydrogen bonding

Quantitative thermodynamic data on the hydrogen bonding of tetra-n-heptylammonium iodide with various hydroxy compounds have been obtained. The importance of hydrogen bonding in explaining the solvent effects on the C.T.T.S. transition of the iodide ion has been pointed out. Some aspects of the electronic transitions of the iodide ion have also been discussed.

Surjit Singh, Cnr Rao 1966Article

Corrigendum to “Electroluminescence from GaN-polymer heterojunction” [J. Lumin. 131 (2011) 2612–2615]

Basant Chitara, Nidhi Lal, S. B. Krupanidhi et al. 2012Corrigendum

CCDC 257633: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

M. Dan, G. Cottereau, Cnr RaoDataset

Novel experiments with carbon nanotubes: opening, filling, closing and functionalizing nanotubes

Carbon nanotubes have been opened using a variety of oxidants including and at room temperature. The opened nanotubes have been filled with metals such as Ag, Au, Pd and Pt by simple chemical means. The opened nanotubes, containing a high concentration of acidic functional groups, get covered or closed by reaction with reagents such as ethylene glycol. The opened nanotubes can also be closed by treatment with benzene vapour in a reducing atmosphere of argon and hydrogen at high temperatures. Refluxing carbon nanotubes in a - mixture results in a clear colourless solution, which on removal of the solvent and excess acid gives a white solid containing functionalized nanotubes. Neutralization of the acidic solution by alkali results in the precipitation of a brown solid containing nanotubes.

B. C. Satishkumar, A. Govindaraj, J Mofokeng et al. 1996Article

Investigations of diamond-graphite hybrids and fullerenes with seven-membered rings

The nature of diamond-graphite hybrids has been studied by molecular mechanics, by examining the structures of species such as C84H x wherein the sp3 to sp2 carbon ratio is varied progressively. The dependence of the average coordination number on the atom fraction of hydrogen has been examined in the light of the random covalent network model. The HOMO-LUMO gap has been estimated in a graphite-like C110H x and in a diamond-like C120H x as a function of the sp 3 sp 2 carbon atom ratio. The gap increases exponentially with the fraction of sp3 carbon. Shapes of fullerene-like structures with 7-membered rings, in addition to 6- and 5-membered rings, have been investigated along with structures of bent nanotubes having similar ring systems.

Rahul Sen, R. Sumathy, B. C. Satishkumar et al. 1997Article

Transition Metal Oxides

No abstract is provided for this article.

Cnr Rao 1989Article

Electronic Spectra of Radical Ions

Organic molecules may accept an extra electron to form radical anions, R+, or give up an electron by ionization to form radical cations, R+. Some of the radical ions are relatively stable in their ground states in solution phase and can be readily characterized by spectroscopic methods. Electron spin resonance spectroscopy provides an ideal tool for the study of the unshared electron in these radical ions. Most radical ions are intensely colored and give characteristic absorption bands in the electronic spectra. Further, electronic spectroscopy is one of the few tools available for the study of the dianions, which are generally diamagnetic. Electronic spectroscopy is used not merely for the characterization of the ionic species in solution but also for the study of the chemical equilibria involving various kinds of ionic species.

Cnr Rao, V. Kalyanaraman, M. V. George 1970Article

Supercapacitors based on nitrogen-doped reduced graphene oxide and borocarbonitrides

Nitrogen-doped reduced graphene oxide (RGO) samples with different nitrogen content, prepared by two different methods, as well as nitrogen-doped few-layer graphene have been investigated as supercapacitor electrodes. Two electrode measurements have been carried out both in aqueous (6M KOH) and in ionic liquid media. Nitrogen-doped reduced graphene oxides exhibit satisfactory specific capacitance, the values reaching 126F/g at a scan rate of 10mV/s in aqueous medium. Besides providing supercapacitor characteristics, the study has shown the nitrogen content and surface area to be important factors. High surface-area borocarbonitrides, B x C y N z , prepared by the urea route appear to be excellent supercapacitor electrode materials. Thus, BC4.5N exhibits a specific capacitance of 169F/g at a scan rate of 10mV/s in aqueous medium. In an ionic liquid medium, nitrogen-doped RGO and BC4.5N exhibit specific capacitance values of 258F/g and 240F/g at a scan rate of 5mV/s. The ionic liquid enables a larger operating voltage range of 0.0–2.5V compared to 0.0–1V in aqueous medium.

K. Gopalakrishnan, Kota Moses, A. Govindaraj et al. 2013Article

Page 15 of 105

Previous Next