Synthesis, structure and morphology of magnesium ferrite nanoparticles, synthesized via “green” method

In this paper, the synthesis of spinel magnesium ferrite (MgFe2O4) nanoparticles is reported, along with its structural, magnetic and hyperthermic properties, which ensure them being effectively used in various fields. Firstly, magnesium ferrite was synthesized via sol-gel auto-combustion method, using honey as the reducing agent. The crystallite size was calculated via the Scherrer method, the modified Scherrer method, the Williamson-Hall method, and the size-strain plot (SSP) method. X-ray analysis was used to confirm the structure of the spinel. For morphological study of ferrite nanoparticles, scanning electron microscopy (SEM) was used. Finally, hyperthermic properties of magnesium ferrite were analyzed for potential usage in medicine. According to these results, spinel magnesium ferrite (MgFe2O4) nanoparticles proved to be suitable for destruction of cancer cells, as they can be heated to the desired temperature, which will increase the sensitivity of those cells.

Synthesis and Characterisation of Structural and Electrical Properties of CuMn2O4 Spinel Compound

CuMn2O4 was synthesized by the solid-state method. MnO2 and CuO were used as precursors. The optimum temperature of synthesis was 850°C. XRD results showed that the prepared compound had a cubic structure with Fd3 ̅m space group. The lattice constant and unit cell volume were a=8.359Å and V=584.14A°3 respectively. The grain size was calculated by the Debye-Scherrer method and was 33.49 nm for CuMn2O4 annealed at 850°C. The experimental density was calculated and compared to the theoretical density. The results were ρt= 5.399 gr/cm3 and ρE = 5.24 gr/cm3. The electrical properties of the compound showed that it behaves like a semiconductor, and the activation energy of the compound was 0.1535 eV. KEYWORDS Activation energy, copper manganite (CuMO), mixed oxide, solid-state reaction, spinel

Comparing Methods for Calculating Nano Crystal Size of Natural Hydroxyapatite Using X-Ray Diffraction

We report on a comparison of methods based on XRD patterns for calculating crystal size. In this case, XRD peaks were extracted from hydroxyapatite obtained from cow, pig, and chicken bones. Hydroxyapatite was synthesized through the thermal treatment of natural bones at 950 °C. XRD patterns were selected by adjustment of X-Pert software for each method and for calculating the size of the crystals. Methods consisted of Scherrer (three models), Monshi–Scherrer, three models of Williamson–Hall (namely the Uniform Deformation Model (UDM), the Uniform Stress Deformation Model (USDM), and the Uniform Deformation Energy Density Model (UDEDM)), Halder–Wanger (H-W), and the Size Strain Plot Method (SSP). These methods have been used and compared together. The sizes of crystallites obtained by the XRD patterns in each method for hydroxyapatite from cow, pig, and chicken were 1371, 457, and 196 nm in the Scherrer method when considering all of the available peaks together (straight line model). A new model (straight line passing the origin) gave 60, 60, and 53 nm, which shows much improvement. The average model gave 56, 58, and 52 nm, for each of the three approaches, respectively, for cow, pig, and chicken. The Monshi–Scherrer method gave 60, 60, and 57 nm. Values of 56, 62, and 65 nm were given by the UDM method. The values calculated by the USDM method were 60, 62, and 62 nm. The values of 62, 62, and 65 nm were given by the UDEDM method for cow, pig, and chicken, respectively. Furthermore, the crystal size value was 4 nm for all samples in the H-W method. Values were also calculated as 43, 62, and 57 nm in the SSP method for cow, pig, and chicken tandemly. According to the comparison of values in each method, the Scherrer method (straight line model) for considering all peaks led to unreasonable values. Nevertheless, other values were in the acceptable range, similar to the reported values in the literature. Experimental analyses, such as specific surface area by gas adsorption (Brunauer–Emmett–Teller (BET)) and Transmission Electron Microscopy (TEM), were utilized. In the final comparison, parameters of accuracy, ease of calculations, having a check point for the researcher, and difference between the obtained values and experimental analysis by BET and TEM were considered. The Monshi–Scherrer method provided ease of calculation and a decrease in errors by applying least squares to the linear plot. There is a check point for this line that the slope must not be far from one. Then, the intercept gives the most accurate crystal size. In this study, the setup of values for BET (56, 52, and 49 nm) was also similar to the Monshi–Scherrer method and the use of it in research studies of nanotechnology is advised.

Revealing inconsistencies in X-ray width methods for nanomaterials

Since the landmark development of the Scherrer Method a century ago, multiple generations of width methods for X-ray diffraction originated to non-invasively and rapidly characterize the property-controlling sizes of nanomaterials.

Synthesis and Characterization of Al2O3 Nanoparticles and Water-Al2O3 Nanofluids for Nuclear Reactor Coolant

A study on synthesis and characterization of Al2O3nanoparticles for water-Al2O3nanofluids as an alternative nuclear coolant has been done. The Al2O3nanoparticles were synthesized from AlCl3using sol gel method utilizing sugar as chelating agent. The Al2O3nanoparticles were mixed with water to produce nanofluids. XRD data showed that the Al2O3nanoparticles crystallize in gamma alumina with crystallite size of 5.5 nm (Debye Scherrer method). Surface area of the Al2O3nanoparticles was 90 m2/gram. Data of TEM showed that the particle size was smaller than 10 nm and the nanoparticle formed agglomerate with size of 60-100 nm. According to zeta potential data, the nanofluids were stable at pH 2.6-7.5 with zeta potential of 28-51 mV. The height of the nanofluid surface decreased about 20 % after 6 days. The thermal conductivity of the water-Al2O3nanofluids produced in this study increased about 2.4-9.7 % compared to that of water.

Pure and La3+/Nd3+ Doped SrTiO3 Powders Obtained by Solid State Reaction and Microwave Assisted Hydrothermal Synthesis

Strontium titanate ceramic powders (SrTiO3), pure and doped with lanthanum (La3+) and neodymium (Nd3+), were synthesized by solid state reaction (SSR) and microwave assisted hydrothermal technique (MHT). For SSR, a mixture of SrCO3, TiO2, La2O3and Nd2O3oxides was performed in stoichiometric ratio, to produce SrTiO3(STO), Sr0.96La0.04TiO3(STO-04La), Sr0.96Nd0.04TiO3(STO - 04Nd) and Sr0.96La0.02Nd0.02TiO3(STO-02La02Nd), in a ball mill, for 3.5 h. This mixture was dried at 70°C for 24h. This powder was calcined at 1150°C for 2h in a conventional oven. For MHT synthesis, Ti (C4H9O)4, SrCO3, La2O3and Nd2O3precursors were solubilized in nitric acid (10M), in stoichiometric proportions to form STO , STO-04La, STO-04Nd and STO-02La02Nd. This solution was precipitated adding NH4OH (10M). Quota of 2g of precipitated powder was then dried in an air oven at 70°C for 24 hours, and then added to 40 ml of a KOH solution (10M). These suspensions were subjected to MHT for 1h, at 120°C. The ceramic powders obtained by the two routes were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The crystallite size was calculated by Scherrer method and from SEM image, linear intercept method for both the SSR and MHT powders was used to measure the particles size, which show the increase of particles size related to the cation substitution.

The thermal annealing effect on Crystal Structure and Morphology of Titanium Dioxide (TiO2) powder

In this research, crystal structure and morphology of TiO2 (powder) has been observed. TiO2 (powder) was heated by furnace unit at temperature 200 °C - 400 °C to obtain the relation of temperature influences to crystallty and morphology of TiO2. Structural characterization has been done using XRD whereas morphology using Scanning Electron Microscope (SEM) method. The result of this research showed that form of the TIO2 structure was polycrystalline in which mostly dominated by crystal structure (101). Scherrer method used to obtain information that at temperature 300oC, TiO2 has a real small particle size less than 10 nm and large pore size to serve the purpose of photocatalyst material. Keywords : Crystal structure,crystalline size, photocatalyst, morphology, SEM, TiO2.

Synthesis of Fe2O3/C Nanocomposite Using Microwave Assisted Calcination Method

Fe2O3/C nanocomposites were successfully synthesized using microwave assisted calcination method. Ferric (III) chloride hexahydrate (FeCl36H2O), sodium hydroxide (NaOH), and dextrose monohydrate (C6H12O6H2O) were used as precursors. A microwave oven of 2.445 GHz with a power of 600 W for 20 minutes was employed during the syntheses. Calcination was performed in a simple furnace at 350 °C for 30 min. The molar ratio of C:Fe is the only process parameter. From Scanning Electron Microscope images, the average particle size were 199 nm and 74 nm for the samples with molar ratio of C:Fe of 1:2 and 1:1, respectively. X-ray diffractometer spectra showed that the obtained samples have γ-Fe2O3 (maghemite) crystal structure. Using the Scherrer method, the crystallite size were 61.7, 58.8, 52.5, and 48.8 nm for the samples with the molar ratios of C:Fe of 1:3, 1:2, 1:1, and 2:1, respectively. It means that the crystallite size of the nanocomposite decreases with the increase of the molar ratio of carbon to iron (C:Fe). The Brunauer-Emmett-Teller characterization showed that the surface area as high as 255.6 m2/g is achieved by of the Fe2O3/C nanocomposite with the molar ratio of C:Fe of 1:1.

Characteristics of Water-ZrO2 Nanofluids with Different pH Utilizing Local ZrO2 Nanoparticle Prepared by Precipitation Method

Changing water as the conventional nuclear reactor coolant with nanofluid in order to increase the efficiency of heat transfer in the nuclear reactors becomes a strong need. In this work, a study of synthesis and characterization of ZrO2 nanoparticle and water-ZrO2 nanofluid was done. The ZrO2 nanopowder was synthesized using a precipitation method from ZrOCl2.8H2O (ZOC) that was prepared from local zircon (ZrSiO4) using caustic fusion method with calcination temperature of 800°C. The ZrO2 nanoparticle contained two phases namely cubic and monoclinic with crystallite size of 12 nm measured using Debye Scherrer method. Stability of nanofluids that prepared by mixing the ZrO2 nanoparticle with water depended on pH. The nanofluids with pH less than 5 and larger than 8 were stable. Sedimentation test showed that the Water-ZrO2 nanofluid produced in this study was very stable until at least 9 days. A typical basic nanofluid has zeta potential of about-41 mV and a typical acidic one has zeta potential of +45 mV. Thermal conductivity of the nanofluids was 4-9 % larger than that of water.