Salt-assisted rapid transformation of NaYF4:Yb3+,Er3+ nanocrystals from cubic to hexagonal

CrystEngComm ◽  
2014 ◽  
Vol 16 (36) ◽  
pp. 8348-8355 ◽  
Author(s):  
Bangda Yin ◽  
Wenli Zhou ◽  
Qian Long ◽  
Chengzhi Li ◽  
Youyu Zhang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Solvothermal Synthesis ◽  
Molar Ratio ◽  
High Quality ◽  
One Pot ◽  
Rapid Transformation

High-quality hexagonal nanocrystals (β-NaYF4:Yb3+,Er3+) were prepared through one-pot mild solvothermal synthesis. The crystal structure of NaYF4:Yb3+,Er3+ can be controlled by changing the molar ratio of phosphate to Ln3+ (Ln3+ represents the total amount of Y3+ and the doped rare earth elements such as Yb3+, Er3+).

Structure Maps and Phase Stability in AlTi3 Alloyed with Rare-Earth Elements

1988 ◽  
Vol 133 ◽  
Author(s):  
C. T. Liu ◽  
J. A. Horton ◽  
D. G. Petitifor
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Solubility Limit ◽  
Size Factor ◽  
X Ray Diffraction ◽  
Atomic Size ◽  
X Ray ◽  
Dependent Parameter ◽  
Rare Earth Additions

ABSTRACTRare-earth elements including Y, Er and Sc were added to AlTi3 for stabilizing the Ll2 ordered crystal structure, as predicted by the AB3 structure map. The crystal structure and phase composition in the AlTi3 alloys were studied by electron microprobe analysis, X-ray diffraction and TEM. The solubility limit of the rare-earth elements were determined and correlated with the atomic size factor. The results obtained so far indicate that rare-earth additions are unable to change the crystal structure of AlTi3 from DO19 to Ll2. The inability to stabilize the Ll2 structure demonstrates the need to characterize the structure map domains with a further period-dependent parameter.

Hexagonal-phase NaREF4 upconversion nanocrystals: the matter of crystal structure

Nanoscale ◽  
2021 ◽  
Author(s):  
Rui Shi ◽  
Carlos D S Brites ◽  
Luis Antonio Dias Carlos
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Hexagonal Phase ◽  
Upconversion Nanocrystals ◽  
Luminescence Performance

The hexagonal-phase (β) of NaREF4 upconversion nanocrystals (RE = rare earth elements) has been widely employed because of the outstanding luminescence performance, yet less is known about the essence of...

scholarly journals Effects of Rare Earth Elements on Properties of High Quality Ingots

1976 ◽  
Vol 62 (7) ◽  
pp. 827-835 ◽  
Author(s):  
Moriyuki ISHIGURO ◽  
Masaharu ITO ◽  
Tatsumi OSUKA
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
High Quality

Quasimonochromatic Radiation for Dental Radiography

1976 ◽  
Vol 55 (1) ◽  
pp. 148-153 ◽  
Author(s):  
A. Huen ◽  
E.J. Sternglass ◽  
D.M. Mazzocco ◽  
W.G. Fischer
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Computer Program ◽  
Dental Radiography ◽  
Monochromatic Radiation ◽  
High Quality ◽  
Skin Exposure ◽  
Dental Radiograph

To obtain a high quality dental radiograph, it is advantageous to use 40 kiloelectron volt (kev) monochromatic radiation. The feasibility of obtaining this type of radiation by filtering rays of rare earth elements was studied by a computer program before experimentation. By use of 40 kev monochromatic radiation, skin exposure was reduced by a factor of two to three.

A petrological and geochronological study of a 360 Ma metallogenic event in Maritime Canada with implications for lithophile-metal mineralization in the Canadian Appalachians

2013 ◽  
Vol 50 (11) ◽  
pp. 1147-1163 ◽  
Author(s):  
Daniel J. Kontak ◽  
Richard J. Horne ◽  
Robert A. Creaser ◽  
Joseph A. Petrus ◽  
Douglas Archibald
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Molar Ratio ◽  
Transition Elements ◽  
Mount Pleasant ◽  
Geochronological Study ◽  
Magmatic Reservoir ◽  
World Class ◽  
Meguma Terrane ◽  
Maritime Canada

The occurrence of ca. 360 Ma greisen-related molybdenite mineralization in the Clayton Hill biotite–muscovite leucomonzongranite (<1 km2) is unusual for the southwestern Meguma terrane of the Maritime Appalachians, where 380 Ma granite-related Sn mineralization dominates. The presence of extensive hornfelsing and occurrence of mineralized (Sn–W–Cu–Zn) skarns in the area suggests a larger intrusion occurs at depth. The intrusion and mineralization are constrained to 361 Ma based on concordant Re–Os (molybdenite) and 40Ar/39Ar (muscovite) ages, which equates to other ca. 360 Ma granites in the area, hence magmatism of this age is more widespread than previously considered. The intrusion is highly evolved (74 wt.% SiO2), metaluminous (A/CNK = 1–1.05; A/CNK = molar ratio [Al2O3/(CaO + Na2O + K2O)]) and depleted in cafemic and transition elements. Rare-earth elements (∑REE = 106–23 ppm) are strongly fractionated with light rare-earth elements (LREE) enriched (La/LuN = 10), and negative Eu anomalies. Biotite is Fe-rich (Fe/(Fe + Mg) = 0.75), and both biotite and muscovite are F deficient. These geochemical features indicate affinity to the other 360 Ma granites and suggest a similar petrogenesis with some A-type affinity. Mineralization occurs as molybdenite-bearing greisens and rusty miaroles lined with pyrite and enrichment in Cu–As–Bi–Au. Stable isotopes (O, S) indicate greisen formation at 450 °C from fluids with δ18OH2O = 7‰ and δ34SH2S = 2‰–3‰, which suggests an A- or I-type magmatic reservoir rather than a peraluminous magma. These data indicate the presence of a widespread magmatic event that is 20 Ma younger than the 380 Ma Sn-base metal event in southern Nova Scotia (e.g., East Kemptville). That this event is the same age as the world class Mount Pleasant Mo–Sn–W–Zn–In deposit of southern New Brunswick indicates additional potential for significant granite-related mineralization in this part of Atlantic Canada.

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