scholarly journals STUDY OF THE EFFECT OF TEMPERATURE FOR HYDROTHERMAL SYNTHESIS ON THE PROPERTIES OF MICRO/NANOSTRUCTURED SAMARIUM GARNET FERRITE POWDERS

2019 ◽  
Author(s):  
N. I. Tsidaeva ◽  
◽  
A. T. Nakusov ◽  
S. A. Khaymanov ◽  
A. K. Khubaev ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Effect Of Temperature ◽  
Garnet Ferrite

Shape control of nickel crystals and catalytic hydrogenation performance of ruthenium-on-Ni crystals

CrystEngComm ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Lihua Zhu ◽  
Tuo Zheng ◽  
Jinbao Zheng ◽  
Changlin Yu ◽  
Nuowei Zhang ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Catalytic Hydrogenation ◽  
Shape Control ◽  
Effect Of Temperature ◽  
Nickel Crystals

Nickel crystals with various shapes were obtained via hydrothermal synthesis. The effect of temperature and surfactant on nickel morphology was studied.

Low Temperature Synthesis of PbTiO3 Nanoparticles

2005 ◽  
Vol 475-479 ◽  
pp. 3517-3520
Author(s):  
Yu Jing Sun ◽  
Shi Tian ◽  
Xiao Bing Li
Keyword(s):  
Hydrothermal Synthesis ◽  
Low Temperature ◽  
Hydrothermal Method ◽  
Tetragonal Phase ◽  
Lead Acetate ◽  
Average Diameter ◽  
Effect Of Temperature ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis

PbTiO3 nano-sized powders were synthesized at 150oC by a new hydrothermal [denoted as sol-hydrothermal] method by using modified titanium tetra-n-butoxide and lead acetate as the precursors. Furthermore, tetragonal PbTi0.8O2.6 nano-sized powders were obtained by this method at 80oC. Compared with hydrothermal synthesis, the effect of temperature on the formation of products prepared by sol-hydrothermal was investigated. The characteristics of products were studied by XRD, TEM and SAXS. The results show sol-hydrothermal method choosing acetylacetonate-modified titanium tetra-n-butoxide and lead acetate to form a sol could obtain PbTiO3 in 120nm size and PbTi0.8O2.6 powders with average diameter of 30nm, and both of them are pure tetragonal phase. In addition, PbTi0.8O2.6 could be converted into PbTiO3 gradually after annealed at giving condition.

The effect of temperature on morphology and electrochemical properties of NiCo2S4 by hydrothermal synthesis

2018 ◽  
Vol 11 (03) ◽  
pp. 1850063
Author(s):  
Yanwei Sui ◽  
Haihua Hu ◽  
Yuanming Zhang ◽  
Bin Tang ◽  
Jiqiu Qi ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Current Density ◽  
Level Structure ◽  
Hydrothermal Process ◽  
Effect Of Temperature ◽  
Second Step ◽  
Carbon Sphere

The hydrothermal method, using the template is a conspicuous way to change the morphology of the product, so it is used widely in many reports. The effect of temperature on morphology of NiCo2S4 by hydrothermal synthesis and its electrochemical properties is distinct as high-performance electrode materials for supercapacitors. With the help of the template (carbon sphere), different morphologies of NiCo2S4 under 90[Formula: see text]C, 120[Formula: see text]C and 180[Formula: see text]C were obtained. They have different properties after electrochemical analysis. In order to build a hierarchical multi-level structure, two-step vulcanization was carried out at each temperature, resulting in the difference in the morphology and performance of the six sample of electrodes. The obtained NiCo2S4 electrodes exhibit 1000[Formula: see text]F[Formula: see text]g[Formula: see text] at the current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text] in the second-step of the hydrothermal process under 120[Formula: see text]C, which is superior to the microblocks NiCo2S4 electrode (90[Formula: see text]C, 888[Formula: see text]F[Formula: see text]g[Formula: see text] at the current density of 1[Formula: see text]A[Formula: see text]g[Formula: see text]) and microparticles NiCo2S4 electrode (180[Formula: see text]C, 574[Formula: see text]F[Formula: see text]g[Formula: see text] at the same current density) in the second-step hydrothermal, which shows a high-rate capability (640[Formula: see text]F[Formula: see text]g[Formula: see text] at 20[Formula: see text]A[Formula: see text]g[Formula: see text]). The obtained nanoparticles NiCo2S4 under 180[Formula: see text]C in the first-step hydrothermal electrode had an excellent cycle retention rate (89.7%), although its specific capacitance was lower. At the same time, the specific capacitance of these sample electrodes obtained in the second-step hydrothermal process is superior to those from the first-step. It was mainly attributed to the fact that temperature can influence the morphology by controlling ion exchange. And our experiment aims to use the hydrothermal method and the template method to find a more suitable temperature range to provide more ideas.

The Effect of Temperature and Time on the Formation of TiO2 (B) Nanowires via Hydrothermal Method

2018 ◽  
Vol 280 ◽  
pp. 15-20
Author(s):  
Thida San Nwe ◽  
Matthana Khangkhamano ◽  
Lek Sikong ◽  
Kalayanee Kooptanond
Keyword(s):  
Phase Composition ◽  
Reaction Time ◽  
Hydrothermal Synthesis ◽  
Effect Of Temperature ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Higher Temperature ◽  
Scanning Electron

TiO2(B) nanowires were prepared at 170 °C, 200 °C and 220 °C for 24 h via hydrothermal synthesis to evaluate the effect of temperature on phase composition and morphologies. The effect of reaction time: 24 and 72 h on the formation was also studied at 170 °C. All samples were calcined in air at 400 °C for 2 h. Phase identification was performed using X-ray diffraction (XRD) and morphologies was examined by a scanning electron microscope (SEM). It was found that hydrothermal temperature and time played an important role in defining TiO2phase composition and its morphology. For 24 h hydrothermal synthesis, at low temperature of 170 °C, anatase TiO2nanoparticles were formed, while at higher temperature of 200 and 220 °C, TiO2(B) nanowires with averaged diameter of 49 nm and several micrometers in length were produced. Interestingly at 170 °C, by increasing reaction time to 72 h, anatase TiO2nanoparticles were completely transformed to TiO2(B) nanowires with averaged diameter of 74 nm and 2-4 micrometers in length.

Effect of Temperature and KOH Concentration on Hydrothermal Synthesis of SrTiO3 Dendrites

2012 ◽  
Vol 430-432 ◽  
pp. 225-228
Author(s):  
Lin Lin Yang ◽  
Yu Jiang Wang ◽  
Qi Qun Zou ◽  
Yong Gang Wang
Keyword(s):  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Effect Of Temperature ◽  
Morphology Evolution

SrTiO3dendrites were successfully synthesized by hydrothermal method. An obvious morphology evolution from cubic-like shape to dendrite was observed when KOH concentration varied from 1M to 0.1M at 80°C. A decrease in KOH concentration was found to be favorable for the formation of dendrites. Star-like shape SrTiO3crystals instead of dendrites were obtained when the temperature was lowed to 40°C.

Study of the temperature effect on the morphology and structure of ZnS nanoparticles synthesized by hydrothermal method

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3379-3388
Author(s):  
Claudia J. Bahena-Martínez ◽  
Nayely Torres-Gómez ◽  
Alfredo R. Vilchis-Néstor
Keyword(s):  
Hydrothermal Synthesis ◽  
Temperature Effect ◽  
Hydrothermal Method ◽  
Formation Mechanism ◽  
Zinc Sulphide ◽  
Effect Of Temperature ◽  
Zns Nanoparticles ◽  
Temperature Increment ◽  
Morphology And Structure ◽  
Subsequent Decomposition

AbstractThe control over the materials structure is crucial for the modulation of its properties, in order to achieve this control is important to know the formation mechanism of the material as function of parameters used. For this purpose, the effect of temperature (120, 140, 160 and 180 °C) on the hydrothermal synthesis of zinc sulphide is evaluated and a proposal of the sequence of reactions formation of zinc sulphur is presented. ZnS nanostructures with blend-phase were obtained, the temperature increment induces the growth of the nanostructure ranged between .62 and 12.72 nm, furthermore, increase the crystallinity of the ZnS nanostructures. The proposed reactions suggest the formation of a complex of thioacetamide with the Zn+2 and its subsequent decomposition into ZnS.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

The effect of temperature on high-resolution TEM image contrast

1995 ◽  
Vol 53 ◽  
pp. 640-641
Author(s):  
T. Geipel ◽  
W. Mader ◽  
P. Pirouz
Keyword(s):  
Form Factor ◽  
Inelastic Scattering ◽  
Accurate Method ◽  
Waller Factor ◽  
Effect Of Temperature ◽  
Specimen Thickness ◽  
Influence Of Temperature ◽  
Debye Waller Factor ◽  
Influence Of Temperature On ◽  
Atomic Form Factor

Temperature affects both elastic and inelastic scattering of electrons in a crystal. The Debye-Waller factor, B, describes the influence of temperature on the elastic scattering of electrons, whereas the imaginary part of the (complex) atomic form factor, fc = fr + ifi, describes the influence of temperature on the inelastic scattering of electrons (i.e. absorption). In HRTEM simulations, two possible ways to include absorption are: (i) an approximate method in which absorption is described by a phenomenological constant, μ, i.e. fi; - μfr, with the real part of the atomic form factor, fr, obtained from Hartree-Fock calculations, (ii) a more accurate method in which the absorptive components, fi of the atomic form factor are explicitly calculated. In this contribution, the inclusion of both the Debye-Waller factor and absorption on HRTEM images of a (Oll)-oriented GaAs crystal are presented (using the EMS software.Fig. 1 shows the the amplitudes and phases of the dominant 111 beams as a function of the specimen thickness, t, for the cases when μ = 0 (i.e. no absorption, solid line) and μ = 0.1 (with absorption, dashed line).

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