Sol-gel Processing and Characterization of Alkaline Earth and Rare-earth Fluoride Thin Films

1999 ◽  
Vol 14 (4) ◽  
pp. 1610-1616 ◽  
Author(s):  
Munehiro Tada ◽  
Shinobu Fujihara ◽  
Toshio Kimura
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Alkaline Earth ◽  
Heating Temperature ◽  
Sol Gel ◽  
Chemical Species ◽  
Earth Metal ◽  
Homogeneous Solutions ◽  
Rare Earth Fluoride ◽  
Earth Fluoride

Alkaline earth and rare-earth fluoride thin films were prepared on silica glass substrates by a sol-gel process using trifluoroacetic acid (TFA) as a fluorine source. Homogeneous solutions were obtained by stirring a mixture of alkaline earth or rare-earth metal acetates, TFA and H2O, dissolved in isopropanol. The solutions were spin-coated and heated at 300–800 °C. The fluoride thin films were obtained by heat treatment around 400 °C in air. The crystallization behavior, the surface morphology, and the optical properties of the films depended on the heating temperature as well as the chemical species of the metal ions.

BaCaLu2F10:Ln3+ (Ln = Eu, Dy, Tb, Sm, Yb/Er, Yb/Ho) spheres: ionic liquid-based synthesis and luminescence properties

CrystEngComm ◽  
2018 ◽  
Vol 20 (40) ◽  
pp. 6173-6182 ◽  
Author(s):  
Wei Liu ◽  
Qi Sun ◽  
Ming Yan ◽  
Yanhua Song ◽  
Xiuqing Zhou ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Rare Earth ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Luminescence Properties ◽  
Alkaline Earth Metal ◽  
Hydrothermal Route ◽  
Rare Earth Fluoride ◽  
Earth Fluoride

Alkaline earth metal rare earth fluoride BaCaLu2F10:Ln3+ (Ln = Eu, Dy, Tb, Sm, Yb/Er, Yb/Ho) submicrospheres with uniform morphology and size were synthesized via a facile ionic liquid-based hydrothermal route. The down- and up-conversion luminescence has been investigated.

The properties of rare-earth fluoride thin films on GaAs substrates for possible MIS use

Vacuum ◽  
1990 ◽  
Vol 40 (6) ◽  
pp. 517-520 ◽  
Author(s):  
VM Koleshko ◽  
AV Gulai ◽  
VI Lyakh
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Rare Earth Fluoride ◽  
Gaas Substrates ◽  
Earth Fluoride

scholarly journals Effect of Alkaline Earth Metal on AZrOx (A = Mg, Sr, Ba) Memory Application

Gels ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 20
Author(s):  
Ke-Jing Lee ◽  
Yeong-Her Wang
Keyword(s):  
Thin Films ◽  
Oxygen Vacancy ◽  
Alkaline Earth ◽  
Sol Gel ◽  
Earth Metal ◽  
Atomic Radius ◽  
High Resistance State ◽  
Alkaline Earth Metal ◽  
Memory Devices ◽  
Metal Insulator Metal

Zr can be stabilized by the element selected, such as Mg-stabilized Zr (MSZ), thus providing MSZ thin films with potentially wide applications and outstanding properties. This work employed the element from alkaline earth metal stabilized Zr to investigate the electrical properties of sol–gel AZrOx (A = alkaline earth metal; Mg, Sr, Ba) as dielectric layer in metal-insulator–metal resistive random-access memory devices. In addition, the Hume–Rothery rule was used to calculate the different atomic radii of elements. The results show that the hydrolyzed particles, surface roughness, and density of oxygen vacancy decreased with decreased difference in atomic radius between Zr and alkaline earth metal. The MgZrOx (MZO) thin film has fewer particles, smoother surface, and less density of oxygen vacancy than the SrZrOx (SZO) and BaZrOx (BZO) thin films, leading to the lower high resistance state (HRS) current and higher ON/OFF ratio. Thus, a suitable element selection for the sol–gel AZrOx memory devices is helpful for reducing the HRS current and improving the ON/OFF ratio. These results were obtained possibly because Mg has a similar atomic radius as Zr and the MgOx-stabilized ZrOx.

scholarly journals Surface and Optical Properties of Gd-Doped ZrO2 Nano Films

2020 ◽  
Vol 4 (1) ◽  
pp. 4
Author(s):  
Ognian Dimitrov ◽  
Irina Stambolova ◽  
Sasho Vassilev ◽  
Katerina Lazarova ◽  
Silvia Simeonova
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Sol Gel ◽  
Earth Metal ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Average Roughness ◽  
Force Microscopy ◽  
Atomic Force ◽  
Skin Conditions

Nanosized coatings of ZrO2 were deposited on silicon substrates using sol-gel and spin coating techniques. The precursor solutions were prepared from ZrOCl2.8H2O with the addition of different percentage (0.5–5%) of rare earth Gd3+ ions as dopant. The thin films were homogeneous, with average thickness of 115 nm and refractive index (n) of 1.83. The X-ray diffraction analysis (XRD) revealed the presence of a varying mixture of monoclinic and tetragonal ZrO2 polycrystalline phases, depending on the dopant, all of which with nanosized crystallites. Scanning electron microscopy (SEM) as well as atomic force microscopy (AFM) methods were deployed to investigate the surface morphology and roughness of the thin films, respectively. They revealed a smooth, well uniform and crack-free surface with average roughness of 0.8 nm. It was established that the dopant concentration affects the photoluminescence (PL) properties of the samples. The undoped films exhibited broad violet-blue PL emission, while the addition of Gd3+ ions resulted in new narrow bands in both UV-B and visible light regions, characteristic of the rare earth metal. The intensive emission located at 313 nm can find useful application in medical lamps for treatment of different skin conditions.

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.

scholarly journals Increased hole mobility in anti-ThCr2Si2-type La2O2Bi co-sintered with alkaline earth metal oxides for oxygen intercalation and hole carrier doping

2021 ◽  
Author(s):  
Kota Matsumoto ◽  
Hideyuki Kawasoko ◽  
Noriaki Kimura ◽  
Tomoteru Fukumura
Keyword(s):  
Rare Earth ◽  
Metal Oxides ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Hole Mobility ◽  
Alkaline Earth Metal ◽  
Alkaline Earth Metal Oxides ◽  
Oxygen Intercalation ◽  
Axis Length ◽  
Carrier Doping

Metallic anti-ThCr2Si2-type RE2O2Bi (RE = rare earth) with Bi square nets show superconductivity while insulating La2O2Bi shows high hole mobility, by expanding the c-axis length through oxygen intercalation. In this...

Thermal Decomposition of Rare Earth Fluoride Hydrates

Science ◽  
1959 ◽  
Vol 129 (3352) ◽  
pp. 842-842 ◽  
Author(s):  
W. W. WENDLANDT ◽  
B. LOVE
Keyword(s):  
Thermal Decomposition ◽  
Rare Earth ◽  
Rare Earth Fluoride ◽  
Earth Fluoride

High-pressure Syntheses and Characterization of the Rare-earth Fluoride Borates RE2(BO3)F3 (RE=Tb, Dy, Ho)

2013 ◽  
Vol 68 (11) ◽  
pp. 1198-1206 ◽  
Author(s):  
Ernst Hinteregger ◽  
Michael Enders ◽  
Almut Pitscheider ◽  
Klaus Wurst ◽  
Gunter Heymann ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Rare Earth ◽  
Monoclinic Space Group ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Structure Determinations ◽  
New Compounds ◽  
Rare Earth Fluorides

The new rare-earth fluoride borates RE2(BO3)F3 (RE=Tb, Dy, Ho) were synthesized under highpressure/ high-temperature conditions of 1:5 GPa=1200 °C for Tb2(BO3)F3 and 3:0 GPa=900 °C for Dy2(BO3)F3 and Ho2(BO3)F3 in a Walker-type multianvil apparatus from the corresponding rareearth sesquioxides, rare-earth fluorides, and boron oxide. The single-crystal structure determinations revealed that the new compounds are isotypic to the known rare-earth fluoride borate Gd2(BO3)F3. The new rare-earth fluoride borates crystallize in the monoclinic space group P21/c (Z = 8) with the lattice parameters a=16:296(3), b=6:197(2), c=8:338(2) Å , b =93:58(3)° for Tb2(BO3)F3, a= 16:225(3), b = 6:160(2), c = 8:307(2) Å , b = 93:64(3)° for Dy2(BO3)F3, and a = 16:189(3), b = 6:124(2), c = 8:282(2) Å , β= 93:69(3)° for Ho2(BO3)F3. The four crystallographically different rare-earth cations (CN=9) are surrounded by oxygen and fluoride anions. All boron atoms form isolated trigonal-planar [BO3]3- groups. The six crystallographically different fluoride anions are in a nearly planar coordination by three rare-earth cations.

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