Fabrication and ionic conductivity of oriented lanthanum silicate films with apatite-type structure

2016 ◽  
Vol 293 ◽  
pp. 51-55 ◽  
Author(s):  
Mitsumasa Sakao ◽  
Tsuguo Ishihara ◽  
Hideki Yoshioka
Keyword(s):  
Ionic Conductivity ◽  
Type Structure ◽  
Lanthanum Silicate ◽  
Apatite Type

Low-temperature sintering of dense lanthanum silicate electrolytes with apatite-type structure using an organic precipitant synthesized nanopowder

2009 ◽  
Vol 24 (1) ◽  
pp. 237-244 ◽  
Author(s):  
Seung Hwan Jo ◽  
P. Muralidharan ◽  
Do Kyung Kim
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Type Structure ◽  
Degree Of Crystallinity ◽  
Polished Surface ◽  
Synthetic Approach ◽  
Low Temperature Sintering ◽  
Lanthanum Silicate ◽  
Microscopy Images ◽  
Apatite Type

Highly sinterable La10Si6O27 and La10Si5.5M0.5O27 (M = Mg, and Al) nanopowders with apatite-type structure have been synthesized via a homogeneous precipitation method using diethylamine (DEA) as a precipitant. The synthetic approach using an organic precipitant with dispersant characteristics is advantageous in configuring weakly agglomerated nanopowders, leading to desirable sintering activity. X-ray diffraction powder patterns confirmed the single-phase crystalline lanthanum silicate of hexagonal apatite structure at 800 °C, which is a relatively lower calcination temperature compared to conventionally prepared samples. Transmission electron microscopy images revealed particles ∼30 nm in size with a high degree of crystallinity. A dense grain morphology was recognized from the scanning electron microscopy images of the polished surface of the pellets that were sintered at 1400 and 1500 °C for 10 h. This low-temperature sintering is significant because conventional powder processing requires a temperature above 1700 °C to obtain the same dense electrolyte. The doped-lanthanum silicate electrolyte prepared by the DEA process and sintered at 1500 °C for 10 h exhibited electrical conductivity comparable with samples prepared at much higher sintering temperature (>1700 °C).

Structure and ionic conductivity of reactively sputtered apatite-type lanthanum silicate thin films

2014 ◽  
Vol 247 ◽  
pp. 14-19 ◽  
Author(s):  
M.M. Vieira ◽  
J.C. Oliveira ◽  
A.L. Shaula ◽  
B. Trindade ◽  
A. Cavaleiro
Keyword(s):  
Thin Films ◽  
Ionic Conductivity ◽  
Lanthanum Silicate ◽  
Apatite Type

Enhanced ionic conductivity of apatite-type lanthanum silicate electrolyte for IT-SOFCs through copper doping

2016 ◽  
Vol 306 ◽  
pp. 630-635 ◽  
Author(s):  
Xifeng Ding ◽  
Guixiang Hua ◽  
Dong Ding ◽  
Wenliang Zhu ◽  
Hongjin Wang
Keyword(s):  
Ionic Conductivity ◽  
Copper Doping ◽  
Lanthanum Silicate ◽  
Apatite Type

Alkaline-earth-rare-earth silicate and germanate apatites

1967 ◽  
Vol 36 (279) ◽  
pp. 411-421 ◽  
Author(s):  
A. G. Cockbain ◽  
G. V. Smith
Keyword(s):  
Rare Earth ◽  
Alkaline Earth ◽  
Random Distribution ◽  
Type Structure ◽  
X Ray ◽  
Cell Dimensions ◽  
End Members ◽  
Lanthanum Silicate ◽  
Apatite Type

SummaryA number of new alkaline-earth-rare-earth silicate and germanate compounds with the apatite-type structure have been synthesized including a new calcium lanthanum silicate, Ca4La6(SiO4)6(OH)2, which has a 9·63 Å, c 7·12, and c/a 0·740. This has a random distribution of Ca2+ and La3+ over the (4f) and (6h) sites in the lattice. X-ray data are given for Ca4La6(SiO4)6(OH)2 together with cell dimensions for other synthetic silicate and germanate apatites. Silicate apatites with partially occupied or vacant halogen (2a) sites analogous to those of the pyro- morphites have been prepared, and a classification for silicate apatites based on synthetic end-members is proposed.

Catalytic toluene combustion over Pt loaded on lanthanum silicate with apatite-type structure

2019 ◽  
Vol 12 (05) ◽  
pp. 1950074 ◽  
Author(s):  
Kenji Matsuo ◽  
Naoyoshi Nunotani ◽  
Nobuhito Imanaka
Keyword(s):  
Catalytic Activity ◽  
High Water ◽  
Type Structure ◽  
Oxygen Release ◽  
Catalytic Activities ◽  
Water Durability ◽  
Lanthanum Silicate ◽  
Apatite Type

Novel Pt/La[Formula: see text]Si5CoO[Formula: see text]-Al2O3 catalysts were developed for complete toluene combustion, and their catalytic activities were investigated. The introduction of the La[Formula: see text]Si5CoO[Formula: see text] promoter enhanced the reducibility and the catalytic activity due to its oxygen release ability. Among the samples prepared in this study, the 10[Formula: see text]wt.% Pt/10[Formula: see text]wt.% La[Formula: see text]Si5CoO[Formula: see text]-Al2O3 catalyst showed the highest catalytic activity, allowing the complete toluene combustion at 120∘C. In addition, the catalyst possesses high water durability.

Low Temperature Synthesis of Lanthanum Silicate Apatite Type by Modified Sol Gel Process

2014 ◽  
Vol 975 ◽  
pp. 143-148 ◽  
Author(s):  
Agatha Matos Misso ◽  
Daniel Ricco Elias ◽  
Fernando dos Santos ◽  
Chieko Yamagata
Keyword(s):  
Colloidal Silica ◽  
High Efficiency ◽  
Ceramic Body ◽  
Low Cost ◽  
Sol Gel ◽  
Lanthanum Nitrate ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Lanthanum Silicate ◽  
Apatite Type

Rare earth silicate apatite type is a very important and promising material for application as an electrolyte in IT-SOFC (Intermediate Temperature Solid Oxide Fuel Cell). Lanthanum silicate apatite, La9,33Si6O26, exhibits high conductivity and has high efficiency, long term stability, fuel flexibility, low emissions and relatively low cost compared to yttria stabilized zirconia (YSZ - yttria stabilized zirconia), at temperatures between 600 to 800 °C. One of the problems of YSZ is its high operating temperature which results in long starting times and problems of mechanical and chemical compatibility. The interest of investigating lanthanum silicate apatite as an electrolyte is to overcome the problems caused by high temperature operation required by YSZ electrolyte. In the present study, sol-gel method was used to synthesize La9,33Si6O26. Initially, the reagents (sodium silicate and lanthanum nitrate) were mixed to obtain colloidal silica. Then, this gel containing lanthanum nitrate was thermally treated to allow the melting of lanthanum nitrate salt distributed on colloidal silica. The aim of this study was to verify if this method permits the formation of La9,33Si6O26 pure apatite phase, in order to obtain fine powders and uniform particles for further processing and obtaining a ceramic body.

scholarly journals Fabrication of apatite-type lanthanum silicate films and anode supported solid oxide fuel cells using nano-sized printable paste

2014 ◽  
Vol 34 (2) ◽  
pp. 373-379 ◽  
Author(s):  
Hideki Yoshioka ◽  
Hiroyuki Mieda ◽  
Takahiro Funahashi ◽  
Atsushi Mineshige ◽  
Tetsuo Yazawa ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Lanthanum Silicate ◽  
Apatite Type
Sign in / Sign up

Export Citation Format

Share Document