S. Sundar Manoharan

Ferromagnetic La0.6Pb0.4MnO3 thin films with giant magnetoresistance at 300 K

Highly textured, as-deposited

Synthesis, Characterization, and Electrochemical Cycling Behavior of the Ru-Doped Spinel, Li [ Mn2 − x Ru x ] O4 (x = 0 , 0.1, and 0.25)

La_{0.6}Pb_{0.4}MnO_3

Combustion synthesis of fine-particle ceria

thin films have been grown on

White organic light-emitting diodes based on spectral broadening in electroluminescence due to formation of interfacial exciplexes

LaAlO_3

ENHANCED MAGNETORESISTANCE IN AS-DEPOSITED OXYGEN-DEFICIENT LA0.6PB0.4MNO3-Y THIN FILMS

by pulsed laser deposition. The films are ferromagnetic metals below 300 K. Giant negative magnetoresistance of over 40% is observed at 300 K at 6 T.

Preparation of fine particle chromites: A combustion approach

Pure and Ru-doped Li[Mn 2-z Ru x ]O 4 (x = 0.1 and 0.25) spinel compounds are prepared by the high temperature solid-state reaction and characterized by X-ray diffraction (XRD), scanning electron microscopy, Brunauer, Emmett, and Teller surface area, density, IR, Raman spectroscopy, and X-ray absorption spectroscopy. XRD studies show single-phase compounds with the cubic spinel structure and a decrease in (Mn-O) and an increase in (Li-O) bond lengths on Ru doping. The electrochemical cycling behavior of Li[Mn 2-x Ru x ]O 4 is examined by galvanostatic cycling and cyclic voltammetry (CV). The CV shows that the Mn 3+ ↔ Mn 4+ couple lies in the range from ~4.0 to ~ 4.2 V and the spinel-to-double-hexagonal (S-DH) transition at ~ 4.5 V in agreement with results in the literature. The Ru 4+ ↔ Ru 5+ redox couple operates at ~4.3 V vs Li in the spinel structure. The S-DH phase transition is suppressed on Ru doping. Charge-discharge cycling, up to 25 or 40 cycles, in the voltage ranges 3.5-4.3 and 3.5-4.6 V vs Li at 0.14C rate gave initial charge capacities ranging from 118 to 139 mAh g -1 for various x. Compositions with x = 0.1 and 0.25 showed smaller initial capacity loss and smaller capacity fading during cycling as compared to x = 0. For x = 0.25 in the voltage range 3.5-4.6 V and 2-25 cycles, the capacity fade is only 9% thereby showing the beneficial effect of Ru doping, by way of suppression of S-DH transition, participation of Ru-redox couple, and better electronic conductivity of the compound during cycling, in comparison to pure LiMn 2 O 4 .

Ruthenium-induced enhanced magnetization and metal-insulator transition in two-dimensional layered manganites

Fine-particle ceria having narrow size distribution is of interest as polishing material for ophthalmological lenses, television tubes, plates and mirrors [1]. The preparation has been reported of such ceria by the hydrolysis of cerium isopropoxide [2] and cerium nitrate [3, 4] followed by thermal decomposition, as well as by the thermal decomposition of cerium oxalate hydrazinate [5] and cerium hydrazine carboxylate [6]. In this letter we report the preparation of fine-particle, large-surface-area ceria by the combustion process developed for the preparation of

Microwave synthesis and characterization of doped ZnS based phosphor materials

\alpha

Magnetic pair-making double exchange coupling in Ru substituted orthomanganites, La0.7A0.3Mn0.9Ru0.1O3

-alumina [7], aluminates [8], chromites [9] and ferrites [10]. The process involves rapid decomposition of a saturated aqueous solution containing ceric ammonium nitrate and urea

UNUSUAL SUBSTITUTIONAL PROPERTIES OF RU IN THE LA0.7SR0.3MN1-XRUXO3 SYSTEM

(CH_4N_20)