Publications

Superconductivity in $Ba_{1-y}Sr_yPb_{1-x}Bi_xO_3$

Advances in solid state chemistry ; proceedings of the INSA Golden Jubilee Symposium on Solid State Chemistry, New Delhi, December 4-6, 1985

No abstract is provided for this article.

Charge ordering in electron-doped manganates

Electron-doped rare-earth manganates of the type Ca1-xLnxMnO3 (Ln = La, Nd, Gd or Y) with x = 0.2 and 0.3 show charge ordering in the 150 - 270 K range, but the charge-ordering transition temperature, Tco, generally decreases with the decrease in the size of the A-site cations, a trend exactly opposite to that for hole-doped manganates. On the other hand, Tco increases with x or the electron concentration. These trends are also seen for Ca1-xLnxMnO3 compounds (Tco = 300K for x = 0.3) which show transitions to a more distorted orthorhombic structure below Tco. In Ca1-xLnxMnO3, Cr doping does not melt the charge-ordered state, unlike the case for the hole-doped systems. CaMnO2.82, for which electron doping is affected by anion vacancies, appears to show charge ordering at around 200 K.

Ferroelectricity in Bi26-xMxO40-delta (M = Al and Ga) with the gamma-Bi2O3 structure

A Comparative Study of the Magnetic and Electrical Properties of Perovskite Oxides and the Corresponding Two-Dimensional Oxides of <font>K</font>₂<font>NiF</font>₄ Structure

No abstract is provided for this article.

ChemInform Abstract: Three‐Dimensional Organically Templated Open‐Framework Transition Metal Selenites.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A Perspective on the Metal-Nonmetal Transition

This chapter discusses a model that was proposed 30 years ago deceptive in its simplicity and laid the foundations for much of the science underlying the metal–nonmetal transition. The apparent simplicity of the problem—to transform a metal into a nonmetal or insulator, and vice versa—belies the subtlety and complexity of this, the most fundamental of electronic phase transitions in condensed matter. Both experimental and theoretical has moved toward the actual transition between metal and nonmetal, the greater the degree of sophistication of the theoretical constructions. At the level of advanced theoretical treatments, the problem of the disordered and interacting electron gas at finite temperature has emerged as one of the central concerns of modern-day condensed matter science. The chapter highlights the continued effectiveness of simple physical concepts and criteria for identifying and describing key aspects of this quantum phase transition. It discusses that successes can be recorded for the Goldhammer–Herzfeld prescription for metallization. Despite the fact that this criterion is obtained from simple classical discussions, it yields predictions for the metal–nonmetal transition that often agree closely with experiment as well as theoretical estimates from elaborate quantum–mechanical calculations. Finally, it concludes that the range and number of experimental systems traversing the metal–nonmetal transition are continually increasing.

CCDC 277863: 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.

Charge Ordered Nd_0.5Ca_0.5MnO_3: Temperature Dependent Electron Paramagnetic Resonance Studies

We report Electron Paramagnetic Resonance measurements on single crystalline and powder samples of Nd_0.5Ca_0.5MnO_3 across the charge-ordering transition at T_co=240 K down to the antiferromagnetic ordering transition at T_N = 140 K. The changes in the linewidth, g-factor and intensity as functions of temperature are studied to understand the nature of spin-dynamics in the system. We explain the observed large decrease in the linewidth from T_N to T_co in terms of motional narrowing caused by the hopping of the Jahn-Teller polarons yielding an activation energy of E_a = 0.13 eV. Similar analysis of data on Pr_0.6Ca_0.4MnO_3 published earlier gives E_a=0.2 eV. Below T_co, the g-value increases continuously suggesting a gradual strengthening of the orbital ordering. We give a qualitative explanation of the temperature dependence and of the maximum in the asymmetry ratio A/B observed at T_co in single crystal spectra which also supports the themodel of motional narrowing.

Large nonlinear absorption and refraction coefficients of carbon nanotubes estimated from femtosecond z-scan measurements

Nonlinear transmission of 80 and 140fs pulsed light with 0.79μm wavelength through single walled carbon nanotubes suspended in water containing sodium dodecyl sulfate is studied. Pulse-width independent saturation absorption and negative cubic nonlinearity are observed, respectively, in open and closed aperture z-scan experiments. The theoretical expressions derived to analyze the z-dependent transmission in the saturable limit require two photon absorption coefficient β0∼1.4cm∕MW and a nonlinear index γ∼−5.5×10−11cm2∕W to fit the data.

Molecular motion in plastic crystals

No abstract is provided for this article.

Improved field emission characteristics of solvothermally synthesized WO 2.72 nanowires

Polar Effects in the Infrared and the Near Ultraviolet Absorption Spectra of Aliphatic Ketones

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolar Effects in the Infrared and the Near Ultraviolet Absorption Spectra of Aliphatic KetonesC. N. R. Rao, G. K. Goldman, and C. LurieCite this: J. Phys. Chem. 1959, 63, 8, 1311–1312Publication Date (Print):August 1, 1959Publication History Published online1 May 2002Published inissue 1 August 1959https://pubs.acs.org/doi/10.1021/j150578a024https://doi.org/10.1021/j150578a024research-articleACS PublicationsRequest reuse permissionsArticle Views41Altmetric-Citations13LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

1,4-Diazacubane crystal structure rectified as piperazinium

The only reported synthesis of a [<italic>n</italic>]-azacubane, 1,4-diazacubane, on re-examination revealed a disordered piperazine that constitutes the previously reported Ni²⁺ Kagome metal organic framework (MOF).

Rare earth cobaltite catalysts: Relation of activity to spin and valence states of cobalt

Catalytic activities of rare earth cobaltites and related compounds are shown to be related to the spin and valence states of cobalt.

Metal Auger intensity ratios in transition metals and their compounds

Metal Auger intensity ratios of the type I(CVV)/I(CC′V) and I(CVV)/I(CC′C″), where C, C′ and C″ denote core levels and V stands for a valence level, are shown to increase progressively with the number of valence electrons in the metal in the case of second-row transition metals and their oxides. Metal Auger intensity ratios in chalcogenides of transition metals can be correlated by taking the effective atomic charge on the metal into consideration. The possible use of metal Auger intensity ratios in the study of surface oxidation of second-row transition metals is illustrated in the case of zirconium.

A series of metallic oxides of the formula La3LnBaCu5O13+δ (Ln = rare earth or Y)

Oxides of the formula La3 LnBaCu5O13+δ (Ln = Nd, Sm, Gd, Dy, or Y) exhibiting metallic resistivity have been prepared and characterized. In the case of yttrium, a composition close to La2Y2BaCu5O13+δ, which is also metallic, could be prepared.

Orbital ordering as the determinant for ferromagnetism in biferroic <font>BiMnO</font>₃

No abstract is provided for this article.