ChemInform Abstract: ENTHALPIES OF FORMATION OF YTTRIUM NITRATE HEXAHYDRATE AND OF THE YTTRIUM(3+) ION

1977 ◽  
Vol 8 (15) ◽  
pp. no-no
Author(s):  
G. PERACHON ◽  
J. THOUREY ◽  
D. MATHURIN
RSC Advances ◽  
2015 ◽  
Vol 5 (36) ◽  
pp. 28487-28496 ◽  
Author(s):  
Pradip Thakur ◽  
Arpan Kool ◽  
Biswajoy Bagchi ◽  
Nur Amin Hoque ◽  
Sukhen Das ◽  
...  

Electroactive β phase nucleation in cerium/yttrium nitrate hexahydrate salt modified PVDF thin filmsviaformation of hydrogen bonds.


2013 ◽  
Vol 544 ◽  
pp. 3-7 ◽  
Author(s):  
Jin Sheng Li ◽  
Xu Dong Sun ◽  
Shao Hong Liu ◽  
Di Huo ◽  
Xiao Dong Li ◽  
...  

Fine yttrium stearate powder was produced at a relatively low temperature using yttrium nitrate hexahydrate, ammonia and stearic acid as the raw materials. Dispersed Y2O3 nanopowder was synthesized by calcining the yttrium stearate. The formation mechanism of the precursor and the Y2O3 nanopowder was studied by means of XRD, TG-DTA, FT-IR, BET, FE-SEM and HR-TEM. Pure and dispersed Y2O3 nanopowder with an average particle size of 30 nm was produced by calcining the precursor at 600 °C. The particle size increases to about 60 nm with the increase of the calcination temperature to 1000 °C. In the preparation of Y2O3 from yttrium stearate, no water medium is involved, thus capillarity force and bridging of adjacent particles by hydrogen bonds can be avoided, resulting in good dispersion of the particles. The dispersed Y2O3 nanopowder prepared in this work has potential application in phosphors and transparent ceramic materials.


2005 ◽  
Vol 901 ◽  
Author(s):  
Xin Zhang ◽  
Ross Hill

AbstractIn this paper, we present examples of the use of photochemical metal organic deposition to form nanostructured metal oxide films. In the first example, we use two reactions with very different reaction rates to control the nanostructuring, utilizing tantalum (V) tetraethoxide acetylacetonate (as a thermally reactive source of tantalum oxide) and manganese (II) 2-ethylhexanoate (as a photochemically reactive source of manganese oxide). We prepare homogeneous precursor films of tantalum (V) tetraethoxide acetylacetonate and manganese (II) 2-ethylhexanoate and in the dark allow the tantalum complex to react forming tantalum oxide regions. The film is then exposed and the manganese complex is converted to a matrix surrounding the tantalum regions. The resultant structures are characterized by electron microscopy, energy dispersive X-ray spectroscopy and Auger spectroscopy. In the second example, we use two immiscible precursors, zirconium (IV) 2-ethylhexanoate and yttrium nitrate hexahydrate to form nanostructured precursor films. The nanostructuring of these films is apparent from SEM studies. Exposure of these films results in the formation of nanostructured films consisting of a zirconium oxide matrix with encapsulated yttrium oxide.


2019 ◽  
Vol 31 (4) ◽  
pp. 834-838
Author(s):  
K.B. Satishkumar ◽  
T.K. Vishnuvardhan ◽  
B. Rajashekhar ◽  
K. Satish ◽  
Shashidhar ◽  
...  

Nano-yttrium oxide has been synthesized from yttrium nitrate hexahydrate by combustion of Agarics bisporus (mushroom) used as fuel. The precursor yttirium nitrate and fuel in acid medium are combusted in furnace at 400 ºC for 3 h yields yttria nanopowder. Morphology of the reaction products are characterized by SEM and TEM. Synthesized yttria nanoparticle are characterized by UV, FTIR, XRD and EDAX are discussed. The crystallite size obtained nano yttria particles are calculated by Scherer′s equation and compared with Williamson-Hall method.


2021 ◽  
Vol 1065 (1) ◽  
pp. 012019
Author(s):  
R Madhusudhana ◽  
S Lovesome Benedict ◽  
L. Krishnamurthy ◽  
R Gopalakrishne Urs ◽  
L Vinaykumar

2016 ◽  
Vol 48 (3) ◽  
pp. 303-315
Author(s):  
Adela Egelja ◽  
Jelena Majstorovic ◽  
Nikola Vukovic ◽  
Miroslav Stankovic ◽  
Dusan Bucevac

Al2O3-YAG composite was obtained by sintering of porous Al2O3 preforms infiltrated with water solution of aluminium nitrate nonahydrate, Al(NO3)3?9H2O and yttrium nitrate hexahydrate, Y(NO3)3?6H2O. Al2O3 preforms with porosity varying from 26 to 50% were obtained after sintering at temperature ranging from 1100 to 1500?C. Sintering of the infiltrated Al2O3 preforms led to formation of YAG particles due to reaction between Y2O3 and Al2O3 at high temperature. It was found that variation of porosity of alumina preforms and sintering temperature is an effective way to fabricate Al2O3-YAG composite with an unusual combination of properties. Open porosity was in the range 15-35%, specific surface was 0.6-6.1 m2/g, pore size was 150-900 nm whereas compressive strength was from 50 to 250 MPa. The effect of sintering temperature on YAG formation and phase composition were investigated using X-ray diffractometry whereas microstructure of the composite was analysed by scanning electron microscopy.


2013 ◽  
Vol 20 (03n04) ◽  
pp. 1350037 ◽  
Author(s):  
C. ESTHER JEYANTHI ◽  
R. SIDDHESWARAN ◽  
PUSHPENDRA KUMAR ◽  
R. V. MANGALARAJA ◽  
V. SIVA SHANKAR ◽  
...  

Y 3+ doped CeO 2 nanopowders ( Ce 0.9 Y 0.1 O 1.95, abbreviated as YDC) were synthesized by citrate-nitrate-auto combustion process using cerium nitrate hexahydrate, yttrium nitrate hexahydrate and citric acid. The as-synthesized powders were calcined at 700°C and converted into dense bodies followed by sintering at 1200°C. The microstructure of the synthesized powders and sintered bodies were examined by scanning electron microscopy (SEM). The surface morphology of the nanoparticles and clusters were also analysed by transmission electron microscopy (TEM). The particles size of the YDC was found to be in the range from 10 to 30 nm, which is in good agreement with the crystallite size calculated from X-ray peak broadening method. Also, the X-ray diffraction confirmed that the Ce 0.9 Y 0.1 O 1.95 crystallizes as the cubic fluorite structure of pure ceria. The optical absorption by functional molecules, impurities and oxygen vacancies were analysed by FTIR and Raman spectroscopic studies. From the FTIR spectrum, the absorption peak found at 530 cm-1 is attributed to the vibrations of metal-oxygen bonds. The characteristic Raman peak was found to be 468 cm-1, and the minute absorption of oxygen vacancies were observed in the region 500–640 cm-1.


2014 ◽  
Vol 28 (16) ◽  
pp. 1450102 ◽  
Author(s):  
Ali Bahari ◽  
Masoud Ebrahimzadeh ◽  
Reza Gholipur

A synthetic process for the formation of Zr x Y 1-x O y nanostructures is demonstrated by the reaction of yttrium nitrate hexahydrate with zirconium propoxide. The reactions are carried out at temperature 60°C and pressure 0.1 MPa. The energy dispersive X-ray (EDX) spectroscopy measurements confirm formation of Zr x Y 1-x O y nanostructures and the presence of carbonate and hydroxide species which are removed after high temperature anneals. It was found that the oxygen pressure during synthesis plays a determinant role on the structural properties of the nanostructure. This effect is further studied by atomic force microscopy (AFM) measurements and scanning electron microscope (SEM), which showed the formation of an isotopically organized structure. X-ray diffraction (XRD) measurement reveals that these changes in the nanostructural efficiency are associated with structural and compositional changes among the substrate. The dielectric constant as measured by the capacitance–voltage (C–V) technique is estimated to be around 39.05. C–V measurements taken at 1 MHz show the maximum capacitance for the Zr 0.05 Y 0.95 O y film. The leakage current densities were below 10-5 A/cm2 for the Zr 0.05 Y 0.95 O y film.


Author(s):  
Pratibha L. Gai ◽  
M. A. Saltzberg ◽  
L.G. Hanna ◽  
S.C. Winchester

Silica based ceramics are some of the most fundamental in crystal chemistry. The cristobalite form of silica has two modifications, α (low temperature, tetragonal form) and β (high temperature, cubic form). This paper describes our structural studies of unusual chemically stabilized cristobalite (CSC) material, a room temperature silica-based ceramic containing small amounts of dopants, prepared by a wet chemical route. It displays many of the structural charatcteristics of the high temperature β-cristobalite (∼270°C), but does not undergo phase inversion to α-cristobalite upon cooling. The Structure of α-cristobalite is well established, but that of β is not yet fully understood.Compositions with varying Ca/Al ratio and substitutions in cristobalite were prepared in the series, CaO:Al2O3:SiO2 : 3-x: x : 40, with x= 0-3. For CSC, a clear sol was prepared from Du Pont colloidal silica, Ludox AS-40®, aluminium nitrate nonahydrate, and calcium nitrate hexahydrate in proportions to form a final composition 1:2:40 composition.


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