Low-Temperature Solid State Synthesis and Characterization of Superconducting Vanadium Nitride

Superconducting vanadium nitride （VN） is successfully synthesized by a solid-state reaction of vanadium pentox- ide, sodium amide and sulfur in an autoclave at a relatively low temperature （240-400℃）. The obtained samples are characterized by x-ray diffraction, x-ray photoelectron spectroscopy and transmission electron microscopy. The result of the magnetization of the obtained VN product as a function of temperature indicates that the onset superconducting transition temperature is about 8.4K. Furthermore, the possible reaction mechanism is also discussed.

Solid state interfacial reactions in electrodeposited Ni/Sn couples

Ni/Sn couples, prepared by sequentially electroplating Ni layers and Sn layers on metallized Si wafers, were employed to study the microstructures and growth kinetics of Ni-Sn intermediate phases, when the Ni/Sn couples were aged at room temperature or armealed at temperatures from 150 to 225℃ for various times. The results show that the NiSn phase and Ni3Sn4 phase are formed, respectively, in the aged couples and annealed couples. The Ni3Sn4 layer is continuously distributed between the Ni and Sn sides in the annealed Ni/Sn couples. The Ni3Sn4 growth follows parabolic growth kinetics with an apparent activation energy of 39.0 kJ/mol.

Reaction mechanisms for 0.5Li_2MnO_3 ·0.5LiMn_(0.5)Ni_(0.5)O_2 precursor prepared by low-heating solid state reaction

Lithium-excess manganese layered oxides, which are commonly described in chemical formula 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2, were prepared by low-heating solid state reaction. The reaction mechanisms of synthesizing precursors, the decomposition mechanism, and intermediate materials in calcination were investigated by means of Fourier transform infrared spectroscopy （FT-IR）, X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, thermogravimetric analysis （TGA）, and differential scanning calorimetry （DSC）. The major diffraction patterns of 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2 powder calcinated at 720℃ for 15 h are indexed to the hexagonal structure with a space group of R3m, and the clear splits of doublets at （006）/（102） and （108）/（110） indicate that the sample adopts a well-layered structure. FESEM images show that the size of the agglomerated particles of the sample ranges from 100 to 300 nm.

Solid State Reaction Yielding a Mineral Utilizing Silica Obtained from an Agricultural Waste

Wollastonite, a mineral of wide industrial applications was synthesised from rice husk ash silica and limestone. A number of raw batches consisting of these starting materials, in 1:1 molar ratio, were heat treated to produce it through solid state reaction from 900℃ to 1300℃. The conducted reaction was monitored by XRD step by step. Amount of Wollastonite formed at every temperature was also studied to some extent. Analyses of the obtained data indicated that the target mineral formation was quite effective and almost proportional to a rise in temperature up to 1200℃. The results from both, XRD and chemical analysis were found in fair agreement with one another

Synthesis of Mesoporous Chromium Aluminophosphate (CrAlPO) via Solid State Reaction at Low Temperature

Mesoporous chromium aluminophosphate （CrAIPO） was successfully synthesized via solid state reaction （SSR） route at low temperature in the presence of a cationic surfactant cetyltrimethyl ammonium bromide （CTAB） and inorganic sources such as A1C13 · 6H20, CrCI3 · 6H20 and NaH2PO4 · 2H20. Characterizations by means of powder X-ray diffraction （XRD）, N2 adsorption- desorption, high resolution transmission electron microscopy （HR-TEM）, scanning electron micrography （SEM）, energy dispersion spectroscopy （EDS）, thermo-gravimetry （TG）, Fourier transform infrared spectroscopy （FT-IR）, and ultraviolet visible light spectroscopy （UV-Vis） were carried out to understand both the pore characteristics and electron transition route of these obtained materials. The experimental results show that the meso-CrA1PO materials with various Cr/A1 molar ratios possess a mesostructure and a specific surface area of 193 to 310 m2/g corresponding to an average pore size of 5.5 to 2.2 rim, respectively. The maxium content of Cr in meso-CrA1PO materials synthesized via SSR route can achieve 16.7wt%, being significantly higher than that of the meso-CrA1PO prepared via a conventional sol-gel route. Meanwhile, the formation mechanism of the meso-CrA1PO was also proposed.

Synthesis of Lanthanide β-Diketonates by Solid State Reaction at Low Heating Temperature

Solid state reactions between β diketones (HPMBP, HDBM) and LnAc 3· x H 2O(La,Nd: x =3/2;Tb: x =4) have been investigated at low heating temperature. Pure compounds of Ln(PMBP) 3 and Ln(DBM) 3 are obtained by solid state reaction, and characterized by elemental analysis, infrared radiation (IR),X ray diffraction (XRD) and photoacoustic spectra. The solid state reaction properties of β diketones and their influences on the structures of products are discussed.

Effect of NH_4F and Nano-SiO_2 on Morphological Control of α-Al_2O_3 Platelets via Solid-state Reaction

Alpha-alumina(α-Al_2O_3) platelets were prepared via solid-state reaction using pseudo-boehmite as the starting material, while NH_4F and nano-SiO_2 were used as additives, and nitric acid was used as the binder. The effect of these additives on properties of the alumina platelets was determined via scanning electron microscopy, X-ray diffraction, and measurements of the surface area and silicon content. A mechanism governing their role in the synthesis process was proposed. The results indicated that NH_4F could promote the formation of highly crystalline platelets. Addition of nano-SiO_2 could lead to increase in the diameter and reduction in the thickness of the platelets, and could also prevent their transformation to α-Al_2O_3. This addition weakened the effect of NH_4F because of the reaction of nano-SiO_2 with F-species and the formation of volatile SiF_4.

STUDIES ON THE SOLID STATE REACTIONS OF COORDINATION COMPOUNDS： LXIX STEPWISE REACTION OF CuCl_2．2H_2O WITH 2，2＇－BIPYRIDYL

Consecutive reaction between two solids, CuCl2.2H2O and 2,2'-bipyridyl in 1:2 molar ratio proceed in tWo steps: the salt first converts to the mediate, then the mediate turns to the final product.

Solid state interfacial reactions in electrodeposited Cu/Sn couples

Cu/Sn couples, prepared by sequentially electroplating Cu and Sn layers on metallized Si wafers, were employed to study the microstructures, phases and the growth kinetics of Cu-Sn intermediate phases, when electroplated Cu/Sn couples were aged at room temperature or annealed at temperatures from 373 K to 498 K for various time. Only Cu6Sn5 formed in aged couples or couples annealed at temperature below 398 K. The Cu6Sn5 layer was continuous, but not uniform, with protrusions extending into the Sn matrix. When Cu/Sn couples were annealed at temperatures from 423 K to 498 K, two continuous and uniform Cn6Sn5/Cu3Sn layers formed within the reaction region between Sn and Cu. There were many voids near the Cu3Sn/Cu interface and within the Cu3Sn layer. Cu6Sn5 and Cu3Sn formations both follow parabolic growth kinetics with activation energies of 41.4 kJ/mol for Cu6Sn5 and 90.4 kJ/mol for Cu3Sn, respectively.

THE SOLID STATE ALDOL CONDENSATION REACTION OF ACETYLFERROCENE AND AROMATIC ALDEHYDES

The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in solution and eight compounds have been prepared. Their structures have been characterized by UV,IR,1~HNMR,HS and elemental analysis.

Preparing Nano-ZnS by Solid State Reaction at Room Temperature

ZnS nanoparticles were prepared by using solid-state reaction method at room temperature in agate mortar for the first time. The average particle size was about 20nm. This reaction is affected by the structure of reactant, crystal water and defects.

Synthesis and electrochemical performance of 5V spinel LiNi_(0.5)Mn_(1.5)O_4 prepared by solid-state reaction

Spinel compound LiNi0.5Mn1.5O4 with high capacity and high rate capability was synthesized by solid-state reaction. At first, MnCl2·4H2O and NiCl2·6H2O were reacted with (NH4)2C2O4·H2O to produce a precursor via a low-temperature solid-state route, then the precursor was reacted with Li2CO3 to synthesize LiNi0.5Mn1.5O4. The effects of calcination temperature and time on the physical properties and electrochemical performance of the products were investigated. Samples were characterized by thermal gravimetric analysis(TGA), scanning electron microscopy(SEM), X-ray diffractometry(XRD), charge-discharge tests and cyclic voltammetry measurements. Scanning electron microscopy(SEM) image shows that as calcination temperature and time increase, the crystallinity of the samples is improved, and their grain sizes are obviously increased. It is found that LiNi0.5Mn1.5O4 calcined at 800 ℃ for 6 h exhibits a typical cubic spinel structure with a space group of Fd3m. Electrochemical tests demonstrate that the sample obtained possesses high capacity and excellent rate capability. When being discharged at a rate as high as 5C after 30 cycles, the as-prepared LiNi0.5Mn1.5O4 powders can still deliver a capacity of 101 mA·h/g, which shows to be a potential cathode material for high power batteries.

Chemical Kinetic Aspects of Solid State Reaction Producing Wollastonite from Rice Husk Silica and Limestone

An industrial mineral wollastonite (CaSiO3) was produced under solid state conditions from rice husk silica and limestone. Reaction was carried out at 900'C to 1300'C for 1 h. The product batches were subjected to XRD and chemical analysis techniques specific for wollastonite. Mole fractions of different product batches were calculated on the basis of accumulated data to study the kinetics. Specific rate constants and reaction rate were also found out. Various probable models of mechanism for reaction were considered and testified with the laid down criterion for suggesting the suitable one. The resulting data were treated with Arrhenius equation as well and activation energy was calculated--therefrom. In addition to finding it's value from the slope of Arrhenius curve, an alternate method was also applied for this purpose. Both of the values were observed to be comparable. The activation energy required for performed reaction was found to be almost one third of that reported for synthesizing CaSiO3 by using quartz. This referred to the economical preparation of wollastonite by using rice husk as a source of silica instead of quartz.

Preparation of nano-sized cerium and titanium pyrophosphates via solid-state reaction at room temperature

Nano-sized cerium-titanium pyrophosphates Ce1-xTixP2O7 （with x = 0, 0.2, 0.5, 0.7, 0.9, and 1.0） were obtained by grinding a mixture of Ce（SO4）2·4H2O, Ti（SO4）2, and Na4P2O7·10H2O in the presence of surfactant PEG-400 at room temperature, washing the mixture with water to remove soluble inorganic salts, and drying at 100℃. The products and their calcined samples were characterized using ultraviolet-visible spectroscopy （UV-vis）, thermogravimetry and differential thermal analyses （TG/DTA）, X-ray powder diffraction （XRD）, and transmission electron microscopy （TEM）. The results show that nano-sized Ce1-xTixP2O7 behave as an excellent UV-shielding material. Thereinto, the CeP2O7 has the most excellent UV-shielding effect, and the amorphous state of Ce0.8Ti0.2P2O7 can keep at a higher temperature than CeP2O7. Therefore, the stabilization of the amorphous state of the cerium pyrophosphates was carded out by doping titanium. This stabilization is a significant improvement, which enables to apply these amorphous pyrophosphates not only to cosmetics and paints, but also plastics and films.

Electrochemical properties of spinel LiMn_2O_4 and LiAl_(0.1)Mn_(1.9)O_(3.9)F_(0.1) synthesized by solid-state reaction

Two types of spinel cathode powders, LiMn2O4 and LiAl0.1Mn1.9O3.9F0.1, were synthesized by solid-state reaction, X-ray diffraction （XRD） patterns of the prepared samples were identified as the spinel structure with a space group of Fd 3^- m. The cubic lattice parameter was determined from least-squares fitting of the XRD data. The LiAl0.1Mn1.9O3.9F0.1 sample showed a little lower initial capacity, but better cycling performance than the LiMn2O4 sample at both room temperature and an elevated temperature. The Vanderbilt method was used to test the electrochemical conductivity of the LiMn2O4 samples. The electrochemical impedance spectroscopy （EIS） method was employed to investigate the electrochemical properties of these spinel LiMn2O4 samples.

Ultrasonication solid state chemical reaction synthesis and characterization of nanocrystalline Zn(Oxin)_2·2H_2O (zinc 8-quinolinolate)

Under near ambient temperature and ultrasonication, nanocrystalline Zn(Oxin)2·2H2O (zinc 8-quinolinolate) was synthesized by solid state chemical reaction. The particle size distribution was relatively uniform, the morphology of the mare was ball like particle. The phase, particle size and morphology of the prepared nanocrystalline were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron diffraction (ED). The results show that the crystallite product has an average size of about 30 nm. The effects of a series of reaction conditions on the synthesis of Zn(Oxin)2·2H2O by solid state reaction were studied. During the synthesis of nanocrystalline Zn(Oxin)2·2H2O, the solid state reaction conditions such as changing reactant, matching proportion of reactant, adding inert substance, joining a little solvent or surface active solvent and grinding at different times may influence morphology, particle size and the size distribution of final products.

Synthesis of MgO-Al_2O_3/ZSM-5 by Solid State Reaction for Propane Dehydrogenation

Solid-state grinding is a simple and effective method to introduce guest species into the channels of microporous materials through filling.The structure and the surface acidity of the materials were obtained from BET isotherms and NH3-TPD,respectively.XRD,UV-vis,UV diffuse-reflectance,and TEM were used to characterize the phases,and the morphology,respectively.The clustered layers of MgO-Al2O3phases were formed in the internal pore surface and were highly dispersed inside the channels of the ZSM-5 host.So the volume of MgO-Al2O3/ZSM-5 composite was larger than the ZSM-5 zeolite itself and some mesoporous channels appeared when Mg/Al species entered the channels.Meanwhile,new acid sites emerged in MgO-Al2O3/ZSM-5 composite and the acid amount of the sample changed.The improved Pt dispersion and the increased acid content would cause the increase of propane conversion and the modification of selectivity during the reaction.

Strontium ferrite powders prepared from oily cold rolling mill sludge by solid-state reaction method

Oily cold rolling mill （CRM） sludge is one of the pollutants emitted by iron and steel plants. Recycling oily CRM sludge can not only reduce pollution but also bring social and environmental benefits. In this study, using oily CRM sludge as sources of iron oxide, the strontium ferrite powders were synthesized in multiple steps including vacuum distillation, magnetic separation, oxidizing roasting, and solidstate reaction. The optimal technological conditions of vacuum distillation and oxidizing roasting were studied carefully. To consider the effects of Fe203/ SrCO3 tool ratio, calcination temperature, milling time and calcination time on magnetic properties of prepared strontium ferrite powders, the orthogonal experimental method was adopted. The maximum saturation magneti- zation （62.6 mA-m2.g-1） of the synthesized strontium ferrite powders was achieved at the Fe203/SrCO3 mol ratio of 6, 5 h milling time, 1250 ~C calcination temperature, and 1 h calcination time. Strontium ferrite powders syn- thesis method not only provides a cheap, high quality raw material for the production of strontium ferrite powders, but also effectively prevents the environmental pollution.

Effects of Solid-State Reaction Synthesis Processing Parameters on Thermoelectric Properties of Mg_2Si

The Mg_(2)Si-matrix thermoelectric material was synthesized by low temperature solid-state reaction.This paper studies the effects of holding time and reaction temperature on the particle size and the properties of the material,and also studies effects of doping elemental Sb,Te and their doping seqence on the properties of the material.The result shows that excessively high temperature and elongated holding time of solid-state reaction are harmful,there is a range of particle size to ensure optimum properties and the doping sequence of Sb or Te without influencing the properties.

Preparation of NH_4ZrH(PO_4)_2·H_2O via solid-state reaction at low heat and its catalytic performance in the synthesis of butyl acetate

Nanocrystalline NH4ZrH（PO4）2·H2O was obtained by grinding ZrOC12·8H2O and （NH4）2HPO4 in the presence of surfactant PEG-400 via solid-state reaction at room temperature. The product NH4ZrH（PO4）2·H2O and its product of thermal decomposition were characterized using thermogravimetry and differential thermal analyses （TG/DTA）, Fourier transform infrared spectroscopy （FT-IR）, X-ray powder diffraction （XRD）, and transmission electron microscopy （TEM）. Nanocrystalline NHaZrH（PO4）2·H2O with an average particle size of 17 nm was obtained when the product was kept at80℃ for 3 h. Its crystalline framework was stable at temperatures below 250℃. In addition, the catalytic performance of NH4ZrH（PO4）2·H2O in the synthesis of butyl acetate was investigated. The results show that NH4ZrH（PO4）2·H2O behaved as an excellent heterogeneous catalyst in the synthesis of butyl acetate.