On the fluorescence spectrum of uranyl ion contained in some rare-earth chlorides

1965 ◽  
Vol 62 (2) ◽  
pp. 104-111
Author(s):  
R. M. Dixit
Keyword(s):  
Rare Earth ◽  
Fluorescence Spectrum ◽  
Uranyl Ion

Site selective fluorescence and purity of a rare earth garnet crystal

1981 ◽  
Vol 59 (16) ◽  
pp. 2441-2448 ◽  
Author(s):  
L. V. Haley ◽  
B. Jacquier ◽  
J. A. Koningstein
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Fluorescence Spectroscopy ◽  
Fluorescence Spectrum ◽  
Experimental Results ◽  
Garnet Crystal ◽  
Excitation Spectra ◽  
Site Selective

Site selective fluorescence spectroscopy of a crystal of europium gallium garnet containing Cr3+ as an impurity has been carried out. An analysis of the experimental results reveals that the strongest fluorescence spectrum between 590.0 nm and 620.0 nm is due to emission from an Eu3+−Cr3+ pair. Fluorescences of farther removed pairs and that of Eu3+ occupying the 8-coordinated d site and 6-coordinated Ga3+ site are also assigned. Energy transfer between the various sites occurs while the excitation spectra for the R lines of Cr3+ show that extremely fast transfer takes place between the R2 and R1 levels.

Thermal and IR spectroscopic characterization of Kamotoïte

1989 ◽  
Vol 54 (5) ◽  
pp. 1263-1268 ◽  
Author(s):  
Irma Lía Botto ◽  
Alejandro Cesar García ◽  
Michel Deliens
Keyword(s):  
Rare Earth ◽  
Thermal Treatment ◽  
Ir Spectroscopy ◽  
Spectroscopic Characterization ◽  
Uranyl Ion ◽  
Ir Spectroscopic

Kamotoïte-(Y), a new uranyl and rare earth carbonate, has been studied by thermal treatment. The mineral has also been characterized by IR spectroscopy and the presence of the bidentate binding of carbonate to uranyl ion has been confirmed. Likewise, the U-O bond lenght in the uranyl group can be estimated by IR measurements.

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Study of segregation in La1.8Sr0.2CuO4 superconductor by STEM-EDS microanalysis

1987 ◽  
Vol 45 ◽  
pp. 54-55
Author(s):  
T. F. Kelly ◽  
P. J. Lee ◽  
E. E. Hellstrom ◽  
D. C. Larbalestier
Keyword(s):  
Rare Earth ◽  
High Field ◽  
Transport Current ◽  
Total Thickness ◽  
New Class ◽  
Ceramic Superconductors ◽  
Current Densities ◽  
Group Ii ◽  
Eds Microanalysis

Recently there has been much excitement over a new class of high Tc (>30 K) ceramic superconductors of the form A1-xBxCuO4-x, where A is a rare earth and B is from Group II. Unfortunately these materials have only been able to support small transport current densities 1-10 A/cm2. It is very desirable to increase these values by 2 to 3 orders of magnitude for useful high field applications. The reason for these small transport currents is as yet unknown. Evidence has, however, been presented for superconducting clusters on a 50-100 nm scale and on a 1-3 μm scale. We therefore planned a detailed TEM and STEM microanalysis study in order to see whether any evidence for the clusters could be seen.A La1.8Sr0.2Cu04 pellet was cut into 1 mm thick slices from which 3 mm discs were cut. The discs were subsequently mechanically ground to 100 μm total thickness and dimpled to 20 μm thickness at the center.

Microstructural characterization of a cast RENi5-based alloy

1993 ◽  
Vol 51 ◽  
pp. 1176-1177
Author(s):  
G. M. Micha ◽  
L. Zhang
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Microstructural Characterization ◽  
Binary Compound ◽  
Nickel Metal ◽  
Cast Material ◽  
Nickel Metal Hydride ◽  
Transmission Electron ◽  
Cast Condition

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.

Rare Earth Production

1952 ◽  
Vol 44 (3) ◽  
pp. 442-442
Author(s):  
Frank Spedding ◽  
Harley Wilhelm ◽  
Wayne Keller et al
Keyword(s):  
Rare Earth
Sign in / Sign up

Export Citation Format

Share Document