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.

scholarly journals Slow magnetisation relaxation in tetraoxolene-bridged rare earth complexes

2017 ◽  
Vol 46 (40) ◽  
pp. 13756-13767 ◽  
Author(s):  
Maja A. Dunstan ◽  
Elodie Rousset ◽  
Marie-Emmanuelle Boulon ◽  
Robert W. Gable ◽  
Lorenzo Sorace ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Slow Relaxation ◽  
Rare Earth Complexes ◽  
Zero Field ◽  
Ac Magnetic Susceptibility ◽  
Quantum Tunnelling ◽  
Dc Magnetic Field

Two tetraoxolene-bridged dinuclear Dy(iii) complexes exhibit slow relaxation in ac magnetic susceptibility studies with zero-field quantum tunnelling of the magnetisation that is suppressed by the application of a dc magnetic field.

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.

Anomalous Pressure Dependence of Dipolar Relaxation Times in Rare-Earth-Doped Lead Fluoride

1983 ◽  
Vol 51 (20) ◽  
pp. 1892-1895 ◽  
Author(s):  
J. J. Fontanella ◽  
M. C. Wintersgill ◽  
D. R. Figueroa ◽  
A. V. Chadwick ◽  
C. G. Andeen
Keyword(s):  
Rare Earth ◽  
Pressure Dependence ◽  
Relaxation Times ◽  
Lead Fluoride ◽  
Dipolar Relaxation ◽  
Rare Earth Doped

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

Dynamic Light Scattering in 5CB Confined in Disordered Porous Media

1995 ◽  
Vol 407 ◽  
Author(s):  
Fouad M. Aliev ◽  
Vladimir V. Nadtotchi
Keyword(s):  
Phase Transition ◽  
Light Scattering ◽  
Volume Fraction ◽  
Wide Spectrum ◽  
Standard Form ◽  
Relaxation Times ◽  
Slow Relaxation ◽  
Isotropic Phase ◽  
Average Pore ◽  
Dynamical Scaling

ABSTRACTWe performed dynamic and static light scattering measurements in nematic LC (5CB) confined in silica porous glasses with average pore sizes of 1000 A˚ (volume fraction of pores 40%) and 100 A˚ (27%). The experiments show significant changes in physical properties of confined LC. Nematic-isotropic phase transition temperature TNI is depressed by 0.6°C in 1000 A˚ pores compared to that bulk value and this phase transition was not detected at all in 100 A˚ pores. We found that even about 20°C below bulk melting temperature the relaxational processes in confined LC were not frozen. Slow relaxation process which does not exist in the bulk LC and wide spectrum of relaxation times (10−8 –)s appear in both 100 A˚ and 1000 A˚. In 100 A˚ pores slow relaxation exists even at T corresponding to the bulk isotropic phase. Our data can not be described using the standard form of dynamical scaling variable (t/r) but they obey activated dynamical scaling with the scaling variable x = lnt/lnr.

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.

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