New luminescent rare earth activated oxynitridosilicates and oxynitridogermanates with the apatite structure

2012 ◽  
Vol 22 (45) ◽  
pp. 23913 ◽  
Author(s):  
Sébastien Thomas ◽  
Judith Oró-Solé ◽  
Benoit Glorieux ◽  
Veronique Jubera ◽  
Valérie Buissette ◽  
...  
Keyword(s):  
Rare Earth ◽  
Apatite Structure

Vitusite — an apatite derivative structure

1992 ◽  
Vol 56 (383) ◽  
pp. 235-239 ◽  
Author(s):  
Adrian A. Finch ◽  
James G. Fletcher
Keyword(s):  
Rare Earth ◽  
Late Stage ◽  
Sensu Stricto ◽  
Hydrothermal Fluids ◽  
Stable Phase ◽  
Synthetic Analogue ◽  
Apatite Structure ◽  
Phosphate Mineral ◽  
Rare Earth Phosphate ◽  
Rare Earth Substitution

AbstractThe uncommon sodium rare-earth phosphate mineral vitusite-(Ce) (Na3RE(PO4)2) can be considered as the extreme product of sodium and rare-earth substitution in the apatite structure. Lesser amounts of substitution provide sodium and rare-earth-bearing apatites up to about 80 mol.% exchange; beyond this point vitusite is the stable phase. The structure of vitusite, determined previously from a synthetic analogue, can also be considered as a derivative from apatite, but with cations exchanged on sites normally occupied by anions. Vitusite can therefore be considered as a sodium- and rare-earthrich apatite end-member, with a distinct, but apatite-derived, structure, formed in highly persodic and high rare-earth environments. From an examination of the literature on diffusion in apatite, vitusite in principle could be formed from apatitesensu strictoby subsolidus diffusion in response to late-stage NaandRE-rich hydrothermal fluids.

Multiple slow relaxation of magnetization in Dy3+ confined in the crystal matrix of rare-earth-calcium silicates with the apatite structure

2020 ◽  
Vol 49 (6) ◽  
pp. 2014-2023 ◽  
Author(s):  
Pavel E. Kazin ◽  
Mikhail A. Zykin ◽  
Lev A. Trusov ◽  
Alexander V. Vasiliev ◽  
Reinhard K. Kremer ◽  
...  
Keyword(s):  
Rare Earth ◽  
Relaxation Times ◽  
Slow Relaxation ◽  
Apatite Structure ◽  
Crystal Matrix ◽  
Calcium Silicates

Dy3+ reveals slow relaxation of magnetization in both Dy-diluted and Dy-rich silicates with enhanced relaxation times in the latter.

ChemInform Abstract: Crystallographic and Spectroscopic Investigations on Nine Metal-Rare-Earth Silicates with the Apatite Structure Type.

ChemInform ◽  
2015 ◽  
Vol 46 (20) ◽  
pp. no-no
Author(s):  
Maria Wierzbicka-Wieczorek ◽  
Martin Goeckeritz ◽  
Uwe Kolitsch ◽  
Christoph Lenz ◽  
Gerald Giester
Keyword(s):  
Rare Earth ◽  
Structure Type ◽  
Apatite Structure ◽  
Spectroscopic Investigations

scholarly journals Luminescent Hydroxyapatite Doped with Rare Earth Elements for Biomedical Applications

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 239 ◽  
Author(s):  
Ionela Andreea Neacsu ◽  
Alexandra Elena Stoica ◽  
Bogdan Stefan Vasile ◽  
Ecaterina Andronescu
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Biomedical Applications ◽  
High Efficiency ◽  
Luminescent Materials ◽  
Apatite Structure ◽  
Inorganic Component ◽  
Medical Field ◽  
Fluorescent Materials ◽  
Interesting Area

One new, promising approach in the medical field is represented by hydroxyapatite doped with luminescent materials for biomedical luminescence imaging. The use of hydroxyapatite-based luminescent materials is an interesting area of research because of the attractive characteristics of such materials, which include biodegradability, bioactivity, biocompatibility, osteoconductivity, non-toxicity, and their non-inflammatory nature, as well their accessibility for surface adaptation. It is well known that hydroxyapatite, the predominant inorganic component of bones, serves a substantial role in tissue engineering, drug and gene delivery, and many other biomedical areas. Hydroxyapatite, to the detriment of other host matrices, has attracted substantial attention for its ability to bind to luminescent materials with high efficiency. Its capacity to integrate a large assortment of substitutions for Ca2+, PO43−, and/or OH− ions is attributed to the versatility of its apatite structure. This paper summarizes the most recently developed fluorescent materials based on hydroxyapatite, which use rare earth elements (REEs) as dopants, such as terbium (Tb3+), erbium (Er3+), europium (Eu3+), lanthanum (La3+), or dysprosium (Dy3+), that have been developed in the biomedical field.

Crystallographic and Spectroscopic Investigations on Nine Metal-Rare-Earth Silicates with the Apatite Structure Type

2015 ◽  
Vol 2015 (6) ◽  
pp. 948-963 ◽  
Author(s):  
Maria Wierzbicka-Wieczorek ◽  
Martin Göckeritz ◽  
Uwe Kolitsch ◽  
Christoph Lenz ◽  
Gerald Giester
Keyword(s):  
Rare Earth ◽  
Structure Type ◽  
Apatite Structure ◽  
Spectroscopic Investigations

Structure and properties of rare earth silicates with the apatite structure at high pressure

2013 ◽  
Vol 40 (10) ◽  
pp. 817-825 ◽  
Author(s):  
F. X. Zhang ◽  
H. Y. Xiao ◽  
M. Lang ◽  
J. M. Zhang ◽  
Yanwen Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Rare Earth ◽  
Structure And Properties ◽  
Apatite Structure

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.

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