Search results for "lanthanum"
showing 10 items of 78 documents
Temperature and impurity concentration effects on upconversion luminescence in LaInO3 doped with Er3+
2016
In this paper a novel method for synthesis of LaInO3:Er3+ is reported and upconversion luminescence properties of the synthesized material at different temperatures (9–300 K) are studied. The samples were prepared by co-precipitation and subsequent heat treatment of lanthanum, indium and erbium hydroxides. It is shown that the excitation at 980 nm leads to a strong green upconversion luminescence in the material. At the concentrations above 0.1 mol. % of Er3+ the energy transfer upconversion mechanism of the luminescence becomes evident. Further increase of Er3+ content in the material leads to higher red-to-green upconversion luminescence intensity ratio. The mechanisms responsible for the…
Elucidation of reaction process between solid tricalcium silicate and a lanthanum salt solution in connection with the precipitation pH. Extension to…
1993
Abstract Dissolution of tricalcium silicate is strongly accelerated in a La salt solution and releases the amounts of OH, Ca and silicate ions just required to precipitate all of lanthanum at pH 8. It remained to be proved that (1) La silicate hydrate could form at pH 8, and (2) Ca silicate hydrate could not precipitate simultaneously. The plot of silicate hydrate and hydroxide precipitation pH of La, Ca and other elements (Th, Zr) against the dropped volume of K2SiO3 and KOH solution and some physico-chemical characterization methods bring affirmative answers to these questions and allow the immobilization process of La and other elements in the presence of tricalcium silicate to be better…
Synthesis and support composition effects on CH4 partial oxidation over Ni–CeLa oxides
2015
Abstract Two series of Ni (6 wt%) catalysts supported over CeO 2 , La 2 O 3 and mixed CeO 2 –La 2 O 3 were prepared by co-precipitation and by wet-impregnation. The effect of the two Ni loading procedures on the catalyst structural properties was investigated by XRD, TPR and XPS. The catalytic behavior of the catalysts was tested in the methane partial oxidation reaction performed at 1 atm in a temperature range of 400–800 °C using dilute feed gas mixture with CH 4 /O 2 = 2 and gas hourly space velocity of 60,000 ml g −1 h −1 . Total methane combustion was observed within the 450 °C ≤ T ≤ 650 °C temperature range. Above 650 °C partial oxidation of methane started to occur, reaching at 80…
UV LED Photo Electron Ionisation for MS and IMS
2009
AbstractA new MEMS ionisation source for spectrometry is presented on the basis of photo electron emission in silicon MEMS. Lanthanum hexaboride ceramic sample and thin nanolayer proved their suitability for photo electron emission in the desired photon energy range of 3.1eV to 3.9eV which correspond to industrially available UV LED. This ionisation source alternative to a Photoionisationdetector (PID) is inspected of its gas ionisation behaviour using gases with an ionisation potential over and under an energy of 10,6eV. To enable the ionisation of the gases the emitted electrons were accelerated to a well-defined energy. The results of these investigations are comparable to the UV dischar…
Structural and morphological properties of Co-La catalysts supported on alumina/lanthana for hydrocarbons oxidation
2004
Abstract Two Al 2 O 3 (24 wt%)–La 2 O 3 (76 wt%) supported Co–La oxides with Co loading 4 wt% and different La content (1 and 9 wt%) were prepared by co-impregnation of the support, the aluminum–lanthanum oxide, with cobalt and lanthanum nitrates in aqueous solution and successive calcination at 800 °C for 4 h. The alumina–lanthana was synthesized by the sol–gel method. The samples were characterized by X-ray diffraction (XRD) and Rietveld refinement in order to identify the crystalline phases and their relative weight. H 2 -TPR (Temperature Programmed Reduction) experiments were recorded with the aim to identify the different Co phases present. Co 3 O 4 and LaCoO 3 were formed for La loadi…
CCDC 995946: Experimental Crystal Structure Determination
2015
Related Article: Maria-Gabriela Alexandru, Diana Visinescu, Marius Andruh, Nadia Marino, Donatella Armentano, Joan Cano, Francesc Lloret, Miguel Julve|2015|Chem.-Eur.J.|21|5429|doi:10.1002/chem.201406088
CCDC 143722: Experimental Crystal Structure Determination
2001
Related Article: T.Grob, G.Seybert, W.Massa, F.Weller, R.Palaniswami, A.Greiner, K.Dehnicke|2000|Angew.Chem.,Int.Ed.|39|4373|doi:10.1002/1521-3773(20001201)39:23<4373::AID-ANIE4373>3.0.CO;2-K
CCDC 1833430: Experimental Crystal Structure Determination
2019
Related Article: Antti Tiihonen, Manu Lahtinen|2019|CrystEngComm|21|2286|doi:10.1039/C8CE01015C
CCDC 1054136: Experimental Crystal Structure Determination
2019
Related Article: Souvik Pal, Kartick Dey, Samia Benmansour, Carlos J. Gómez-García, Hari Pada Nayek|2019|New J.Chem.|43|6228|doi:10.1039/C8NJ05173A
CCDC 1826451: Experimental Crystal Structure Determination
2018
Related Article: Marta Mon, Rosaria Bruno, Rosangela Elliani, Antonio Tagarelli, Xiaoni Qu, Sanping Chen, Jesús Ferrando-Soria, Donatella Armentano, Emilio Pardo|2018|Inorg.Chem.|57|13895|doi:10.1021/acs.inorgchem.8b02409