scholarly journals Effect of heat-treatment on phase formation and crystallization of sol–gel derived Al2O3, ZrO2–Y2O3, and Ta2O5 oxide coatings

2015 ◽  
Vol 3 (2) ◽  
pp. 217-220 ◽  
Author(s):  
Yang-Il Jung ◽  
Hyun-Gil Kim ◽  
Jeong-Yong Park ◽  
Dong-Jun Park ◽  
Jung-Hwan Park
Keyword(s):  
Heat Treatment ◽  
Phase Formation ◽  
Sol Gel ◽  
Oxide Coatings

Sol-Gel Derived Titania/Hydroxyapatite Layer on Titanium Substrate

2011 ◽  
Vol 117-119 ◽  
pp. 332-334 ◽  
Author(s):  
Wen Yan Wang ◽  
Yu Wu ◽  
Jing Pei Xie ◽  
Gao Lu ◽  
Xiao Ming Dong ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Quality ◽  
Phase Formation ◽  
Volume Fraction ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Titanium Substrate ◽  
Gel Method ◽  
Good Surface ◽  
Coating Method

In this study, calcium nitrate(Ca(NO3)2•4H2O) and phosphorus pentoxide(P2O5) were used as precursor to prepare hydroxyapatite(HA) layer by sol-gel method, followed by a dipping-coating method to coat HA layer onto Ti. Phase formation and microstructure were investigated by XRD and SEM to study the influence of atmosphere on the property of HA layer. The results revealed that there exists no large cracks in the layer which was heated in the nitrogen, leading to a good surface quality compared with the layer which was heated in the air. And there is no obvious difference in crystallinity and volume fraction of HA in the layer when adopting heat treatment in different atmospheres.

Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite

2020 ◽  
Vol 92 (1) ◽  
pp. 10901
Author(s):  
Saloua El Asri ◽  
Hamid Ahamdane ◽  
Lahoucine Hajji ◽  
Mohamed El Hadri ◽  
Moulay Ahmed El Idrissi Raghni ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Single Phase ◽  
Sol Gel ◽  
Complex Impedance ◽  
Transmission Spectra ◽  
Electrical Measurements ◽  
Cation Type ◽  
Edx Analyses ◽  
The Fourier Transform

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.

LiNiO2 Thin Films Fabricated by Diffusion of Li on Ni Tapes

2007 ◽  
Vol 336-338 ◽  
pp. 505-508
Author(s):  
Cheol Jin Kim ◽  
In Sup Ahn ◽  
Kwon Koo Cho ◽  
Sung Gap Lee ◽  
Jun Ki Chung
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Sol Gel ◽  
Surface Oxidation ◽  
Cold Isostatic Pressing ◽  
Tube Furnace ◽  
Treatment Conditions ◽  
Average Grain Size ◽  
Cold Rolling And Annealing

LiNiO2 thin films for the application of cathode of the rechargeable battery were fabricated by Li ion diffusion on the surface oxidized NiO layer. Bi-axially textured Ni-tapes with 50 ~ 80 μm thickness were fabricated using cold rolling and annealing of Ni-rod prepared by cold isostatic pressing of Ni powder. Surface oxidation of Ni-tapes were conducted using tube furnace or line-focused infrared heater at 700 °C for 150 sec in flowing oxygen atmosphere, resulted in NiO layer with thickness of 400 and 800 μm, respectively. After Li was deposited on the NiO layer by thermal evaporation, LiNiO2 was formed by Li diffusion through the NiO layer during subsequent heat treatment using IR heater with various heat treatment conditions. IR-heating resulted in the smoother surface and finer grain size of NiO and LiNiO2 layer compared to the tube-furnace heating. The average grain size of LiNiO2 layer was 0.5~1 μm, which is much smaller than that of sol-gel processed LiNiO2. The reacted LiNiO2 region showed homogeneous composition throughout the thickness and did not show any noticeable defects frequently found in the solid state reacted LiNiO2, but crack and delamination between the reacted LiNiO2 and Ni occurred as the reaction time increased above 4hrs.

Preferred Orientations for Sol-Gel Derived Plzt Thin Layers

1993 ◽  
Vol 310 ◽  
Author(s):  
Toshihiko Tani ◽  
Zhengkui Xu ◽  
David A. Payne
Keyword(s):  
Heat Treatment ◽  
Surface Energy ◽  
Sol Gel ◽  
Nucleation And Growth ◽  
Thin Layers ◽  
Energy Conditions ◽  
Chemical Characteristics ◽  
Interfacial Chemistry ◽  
Si Substrates

AbstractPLZT thin layers were deposited onto various substrates by sol-gel methods, and crystallized under different conditions and substrate treatments. Relationships are given for the chemical characteristics of the substrate's surface and the preferred orientations which develop on heat treatment. A preferred (111) orientation always developed for perovskite crystallized on Pt layers which contained Ti on the surface. This was attributed to the formation of Pt3Ti and the role of heteroepitaxial nucleation and growth sites. In addition, a preferred (100) orientation was also obtained on unannealed Pt/Ti/SiO2/Si substrates which were free of Ti on the surface. This was attributed to self-textured growth with flat faces striving for minimum surface energy conditions. The results are discussed in terms of the importance of interfacial chemistry on the control of texture for crystallization of PLZT thin layers on coated substrates.

Sol-gel processing of cordierite: Effect of seeding and optimization of heat treatment

1990 ◽  
Vol 5 (5) ◽  
pp. 1095-1103 ◽  
Author(s):  
Ann M. Kazakos ◽  
Sridhar Komarneni ◽  
Rustum Roy
Keyword(s):  
Heat Treatment ◽  
Single Phase ◽  
Excess Free Energy ◽  
Sol Gel ◽  
Nucleating Agents ◽  
Optimum Conditions ◽  
Nanosized Powders ◽  
Nanocomposite Gels ◽  
Powder Compacts ◽  
Gel Processing

Three series of cordierite powders were prepared by the sol-gel route: a single phase (monophasic) gel prepared from alkoxides, a nominally triphasic nanocomposite gel made with two nanosized powders and one solution phase, and a truly compositionally triphasic nanocomposite gel prepared from three nanosized powders. Crystalline α-cordierite seeds were also incorporated with the gels and their effectiveness as nucleating agents was investigated and found to lower the crystallization temperature of α-cordierite by 125–150°C. The densification behavior of powder compacts was examined and alterations made to the heat treatment until optimum conditions were found. The truly triphasic compact sintered at 1300°C for 2 h resulted in 100% of theoretical density whereas the nominally triphasic and monophasis pellets densified to 96% and 80%, respectively. The enhanced densification achieved with powder compacct prepared for triphasic nanocomposite gels is due to part to the excess free energy of the three components.

scholarly journals Interfacial mechanisms controlling phase formation in sol-gel derived lead zirconate titanate thin films

1994 ◽  
Vol 17 (6) ◽  
pp. 1005-1014 ◽  
Author(s):  
S B Majumder ◽  
V N Kulkarni ◽  
Y N Mohapatra ◽  
D C Agrawal
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Zirconate Titanate

Preparation of Macroprous C12A7 Mayenite Monoliths via a Sol-Gel Process with Nitrates as Precursors

2018 ◽  
Vol 768 ◽  
pp. 211-217 ◽  
Author(s):  
Rui Wang ◽  
Yu Kun Sun ◽  
Bao Jia Qi Jiang ◽  
Hui Yang ◽  
Xing Zhong Guo
Keyword(s):  
Heat Treatment ◽  
Phase Separation ◽  
Binary System ◽  
Propylene Oxide ◽  
Crystalline Phase ◽  
Sol Gel ◽  
Single Crystalline ◽  
Sol Gel Process

Macroporous Ca12Al14O33(C12A7) mayenite monoliths have been successfully prepared via a sol-gel process in the presence of propylene oxide (PO) and poly (ethyleneoxide) (PEO). Gelation of CaO-Al2O3binary system with nitrates salts as additional precursors is accelerated by PO as an acid scavenger, while PEO works as a phase separation inducer to mediate the phase separation of the system. Appropriate PO and PEO amounts allow the formation of monolithic xerogel with interconnected macropores and co-continuous skeletons. The resultant dried gels are amorphous and the single crystalline phase Ca12Al14O33mayenite forms after heat-treatment at 1100 °C in air, while the macrostructure is preserved with a porosity as high as 78% and smoother and denser skeletons.

Characteristics of Lithium Polysilicate Electrolyte Synthesized by Sol-Gel Processing

2007 ◽  
Vol 124-126 ◽  
pp. 1031-1034
Author(s):  
Bong Soo Jin ◽  
Bok Ki Min ◽  
Chil Hoon Doh
Keyword(s):  
Heat Treatment ◽  
Acid Treatment ◽  
Treatment Time ◽  
Sol Gel ◽  
Silicate Solution ◽  
Treatment Temperature ◽  
Lithium Silicate ◽  
Treatment Conditions ◽  
Xrd Patterns ◽  
Si Wafer

To find out suitable Si surface treatment and heat treatment conditions, acid treatment of Si wafer was done for lithium polysilicate electrolyte coating on Si wafer. In case of HCl treatment, the wet angle of a sample is 30o, which is the smallest wet angle of other acid in this experiment. Acid treatment time is 10 min, which is no more change of wet angle. Lithium polysilicate electrolyte was synthesized by hydrolysis and condensation of lithium silicate solution using perchloric acid. Thermal analysis of lithium polysilicate electrolyte shows the weight loss of ~23 % between 400 and 500 , which is due to the decomposition of LiClO4. The XRD patterns of the obtained lithium polysilicate electrolyte also show the decrement of LiClO4 peak at 400 . The optimum heat treatment temperature is below 400 , which is the suitable answer for lithium polysilicate electrolyte.

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