SiO2 Samples Research Articles

Catalytic Production of Levulinic and Formic Acids from Fructose over Superacid ZrO2–SiO2–SnO2 Catalyst

Catalytic conversion of fructose to levulinic and formic acids over tin-containing superacid (H0 = −14.52) mixed oxide was studied. Mesoporous ZrO2–SiO2–SnO2 (Zr:Si:Sn = 1:2:0.4) was synthesized by the sol–gel method. The fructose transformation was carried out in a rotated autoclave at 160–190 °C for 1–5 h using a 20 wt.% aqueous solution. The results showed that doping ZrO2–SiO2 samples with Sn4+ ions improved both fructose conversion and selectivity toward levulinic and formic acids. Under optimal conditions of 180 °C, 3.5 h and fructose to catalyst weight ratio 20:1, levulinic and formic acids yields were 80% and 90%, respectively, at complete fructose conversion. At this, humic substances formed in the quantity of 10 wt.% based on the target products.

Effects of dopants with various valences on densification behavior and phase composition of a ZrO2–SiO2 nanocrystalline glass-ceramic

Effects of dopants with different valences on the densification behavior and phase composition of a ZrO2–SiO2 nanocrystalline glass-ceramic (NCGC) during pressureless sintering were investigated in this study. The raw powder of Ca2+, La3+, Ce4+ and Ta5+ ions doped ZrO2–SiO2 (referred to as Ca-ZS, La-ZS, Ce-ZS, Ta-ZS, respectively) and pure ZrO2–SiO2 (PZS) sample were synthesized by sol-gel method, followed by pressureless sintering. Compared with the PZS sample, doping of Ca2+ and La3+ ions significantly promoted the densification of the NCGCs. The “densification promotion” effect was attributed to the formation of oxygen vacancies and the decrease of SiO2 viscosity due to doping of aliovalent cations. The dopants with various valences showed significant effects on the phase compositions of the NCGCs during sintering. Doping of Ca2+ ion accelerated the reaction kinetics between ZrO2 nanocrystallites and amorphous SiO2 to yield ZrSiO4. The La3+ ion acted as destabilizer of t-ZrO2, which resulted in a rapid tetragonal (t) to monoclinic (m) ZrO2 phase transformation during sintering, while in the Ta5+ and Ce4+ ions doped sample, the phase transformation occurred gradually. All the doping ions increased the lattice parameters and the volume of t-ZrO2 unit cell, while the effects of the doping ions on the lattice parameters of m-ZrO2 unit cell were more complex.

Improvement of light olefins production over the Co‐Ni‐Mn nano‐catalyst: modeling and optimization of process by RSM

AbstractThe co‐precipitated Co‐Ni‐Mn nano‐catalysts were evaluated for carbon monoxide hydrogenation. The influence of Al2O3, SiO2, Zeolite, Active carbon, MgO supports and then the effect of best chosen support loading on the catalytic behavior and structure of ternary Co‐Ni‐Mn nano‐catalysts were studied. The Co‐Ni‐Mn/20 wt%SiO2 sample has shown highest selectivity toward light olefins production. Furthermore the influence of process conditions was investigated. Evaluation tests were performed under process conditions of P = 1–10 bar, T = 523‐623 K, and H2/CO = 0.67–3. The Response Surface Methodology (RSM) method was used for modeling and optimization process and the best conditions for catalyst evaluation were determined (T = 598.16 K, P = 1 atm and H2/CO = 2.19). Under these conditions the highest selectivity of light olefins, higher CO conversion % and lower selectivity toward methane were achieved. Catalysts characteristics were investigated using XRD, BET, TEM, TGA, DSC, SEM, XPS, and TPR techniques. © 2021 Society of Chemical Industry (SCI).

Metal-Free Phosphated Mesoporous SiO2 as Catalyst for the Low-Temperature Conversion of SO2 to H2S in Hydrogen.

Highly active metal-free mesoporous phosphated silica was synthesized by a two-step process and used as a SO2 hydrogenation catalyst. With the assistance of a microwave, MCM-41 was obtained within a 10 min heating process at 180 °C, then a low ratio of P precursor was incorporated into the mesoporous silica matrix by a phosphorization step, which was accomplished in oleylamine with trioctylphosphine at 350 °C for 2 h. For benchmarking, the SiO2 sample without P precursor insertion and the sample with P precursor insertion into the calcined SiO2 were also prepared. From the microstructural analysis, it was found that the presence of CTAB surfactant was important for the incorporation of active P species, thus forming a highly dispersed, ultrafine (uf) phosphate silica, (Si-P) catalyst. The above approach led to the promising catalytic performance of uf-P@meso-SiO2 in the selective hydrogenation of SO2 to H2S; the latter reaction is very important in sulfur-containing gas purification. In particular, uf-P@meso-SiO2 exhibited activity at the temperature range between 150 and 280 °C, especially SO2 conversion of 94% and H2S selectivity of 52% at 220 °C. The importance of the CTAB surfactant can be found in stabilizing the high dispersion of ultrafine P-related species (phosphates). Intrinsic characteristics of the materials were studied using XRD, FTIR, EDX, N2 adsorption/desorption, TEM, and XPS to reveal the structure of the above catalysts.

Highly efficient photo-degradation of cetirizine antihistamine with TiO2-SiO2 photocatalyst under ultraviolet irradiation

Abstract Photocatalysis is an extraordinary and vastly researched topic; there is a need to find new ways to support producing composite materials that are cost-effective, efficient and have a low environmental impact. The investigation was undertaken on syn TiO2 by depositing it on silica. The results elucidate the positive effect on photocatalysis activity and the macroscopic structure on which the TiO2 is formed. For the analysis of photocatalyst, various characterisation measurements were undertaken, such as XRD, FTIR, DRS, FESEM, TEM, RS, and BET. The accumulated TiO2 onto the surface of SiO2 stabilised its transformation of the phase from anatase to rutile, resulting in decreased particle size and enhancing its photocatalytic activity under UV irradiation. The concentration of OH• radicals was determined using terephthalic acid as a probe molecule to determine its role in the photocatalytic degradation of antihistamine. The results of BET analysis showed that the syn TiO2-SiO2 sample has a large specific surface area of 192.6 m2 g−1. Maximum degradation of cetirizine (about 97%) was achieved with 80% TiO2-20% SiO2 (TS-4). Recyclability test confirmed that 80% TiO2-20% SiO2 sample was stable up to six cycles.

Surface Modification of Nanoporous Anodic Alumina during Self-Catalytic Atomic Layer Deposition of Silicon Dioxide from (3-Aminopropyl)Triethoxysilane.

Changes associated to atomic layer deposition (ALD) of SiO2 from 3-aminopropyl triethoxysilane (APTES) and O3, on a nanoporous alumina structure, obtained by two-step electrochemical anodization in oxalic acid electrolyte (Ox sample) are analysed. A reduction of 16% in pore size for the Ox sample, used as support, was determined by SEM analysis after its coverage by a SiO2 layer (Ox+SiO2 sample), independently of APTES or O3 modification (Ox+SiO2/APTES and Ox+SiO2/APTES/O3 samples). Chemical surface modification was determined by X-ray photoelectron spectroscopy (XPS) technique during the different stages of the ALD process, and differences induced at the surface level on the Ox nanoporous alumina substrate seem to affect interfacial effects of both samples when they are in contact with an electrolyte solution according to electrochemical impedance spectroscopy (EIS) measurements, or their refraction index as determined by spectroscopic ellipsometry (SE) technique. However, no substantial differences in properties related to the nanoporous structure of anodic alumina (photoluminescent (PL) character or geometrical parameters) were observed between Ox+SiO2/APTES and Ox+SiO2/APTES/O3 samples.

Cobalt-Doped Silica Organic-Inorganic Materials by Sol-Gel Method: Preparation and Thermal Stability Calcined under N2 Atmosphere

Cobalt-doped silica organic-inorganic (Co/SiO2) materials were prepared by sol-gel technique using tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) as silicon precursors and Co(NO3)2·6H2O as cobalt source. The influence of calcination temperature on the microstructure of Co/SiO2 material under N2 atmosphere was discussed by X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive spectrum (EDS) and thermogravimetric-differential thermogravimetric (TG-DTG) measurements. The results showed that, when calcined at N2 atmosphere, the Co element in the Co/SiO2 material exists not only as the Si-O-Co bond, but also the crystals containing the cobalt element. In the calcing process of 25 ∼ 800 °C, the crystals containing the cobalt element have successively undergone four phase transitions from Co(NO3)2·6H2O to Co3O4, CoO and elemental Co0. The Si-O-Co bonds were formed in the calcined Co/SiO2 materials. The water contact angle on the Co/SiO2 film surface achieved the maximum value of 95.6° when the calcination temperature is at 400 °C. In order to keep the hydrophobicity of Co/SiO2 membrane materials for gas separation, the optimal calcination temperature should be 350 ∼ 400 °C. The Co/SiO2 membrane material calcined at 400 °C has a larger specific surface area, pore volume and mean pore diameter than the SiO2 sample.

Determination of thickness and refractive index of SiO2 thin films using the cross-entropy global optimization method

Silicon dioxide (SiO2) is a material that is abundant in nature and has wide application in semiconductor and insulating devices. In this work, a set of six SiO2 samples were grown on a Sigma-Aldrich Silicon substrate, varying the growth time and temperature. This set of samples were grown using times of 10 and 12h and temperatures of 800, 900, and 1000 ºC, under ambient atmosphere. After film growth, reflectance measurements were performed on the films and the substrate, using the Stellarnet UV-VIS-NIR spectrophotometer between 194 and 1081.5 nm. These measurements were modeled using a global optimization method, called Cross-entropy, together with the Bootstrapping resampling technique, seeking to robustly and statistically determine the thin film refractive index as a function of the wavelength and its thickness. To estimate the refractive index of the SiO2 thin film, the Cauchy model was used. For the substrate, reflectance measurements were used. The method proved to be efficient, presenting thickness values that were validated according to growth parameters and literature data. This method proved to be an important and low-cost tool, compared to traditional methods, to help in the steps of building thin films for semiconductor and insulating devices, thus improving their physical properties and enabling the development of new devices.

Acquisition of artifact free alkali metal distributions in SiO2 by ToF‐SIMS Cs+ depth profiling at low temperatures

Artifact‐free depth profiles of alkali ions in SiO2 were obtained using a time‐of‐flight secondary ion mass spectrometer (ToF‐SIMS) equipped with a Cs+ beam as sputter gun. Samples were set to low temperature (~−100°C) using a heating/cooling sample holder. The effects of temperature on the depth profiles was determined with multiple measurements at different temperatures. To validate the described method, obtained depth profiles of alkali metal implanted SiO2 samples were compared with simulated depth profiles. Evidence for artifact‐free depth profiles is given for potassium, sodium, and lithium, three prominent examples of fast diffusing ions in various materials. This described approach enables more laboratories to acquire depth profiles of alkali metals in non‐conducting samples without time‐consuming sample preparation. It offers artifact‐free depth profiling of alkali metals using a classic ToF‐SIMS without advanced extensions, which are not available in many laboratories.

Changes in Optical Parameters of SiO2:TiO2 Films Obtained by Sol-Gel Method Observed as a Result of Thermal Treatment.

The research focused on materials having potential applications in technology of planar evanescent wave sensors. Four samples of binary SiO2:TiO2 thin films having different titania content were manufactured through the sol-gel method and dip-coating technique on polished silicon substrates. The samples were subjected to repeated heating/cooling protocols. Simultaneously, their optical parameters were monitored by spectroscopic ellipsometry as they evolved under varying temperature. Subsequent analysis confirmed linear dependence of refractive index on titania content, at least in vis-NIR wavelengths, as well as a low value of the thermal expansion coefficient. It was shown that the thickness of SiO2:TiO2 films decreased as a result of annealing processes, which may be a consequence of reduced porosity.

Monte Carlo simulation for the analysis of various solid samples using handheld X-ray fluorescence spectrometer and evaluation of the effect by environmental interferences

Handheld X-ray fluorescence (HH-XRF) has expanded its utilization areas according to recent technological developments. Most current applications, though, are still concentrated in traditional areas including mineral resource analysis and environmental regulation rather than forensic science for the purpose of investigating a nuclear security event involving nuclear material out of regulatory control. To apply HH-XRF to nuclear material analysis, it is necessary to first obtain calibration data using standard reference materials. Considering the difficulty in obtaining such standard reference materials as well as the high costs involved, one well-known alternative method is to use Monte Carlo simulation code. This study investigated the feasibility of employing Monte Carlo N-Particle transport 6 (MCNP6) simulation to provide calibration data through comparison with experimental measurements of pure solid samples of graphite, copper, SiO2, and UO2 using HH-XRF. The results showed that the MCNP6 simulation results were entirely consistent with the measurement spectra, except for environmental interferences stemming from interactions with the mechanical components below 10 keV which varied slightly according to sample type. To quantitatively evaluate the effect of these environmental interferences on the whole spectrum, the coefficient of determination (R2) was used. In the case of graphite, the effect of the environmental interferences was evaluated to be about 20% on the conformity of the measured and simulated results, while those for copper, SiO2, and UO2 were about 1%, 3%, and less than 1%, respectively. These results indicate that samples having elements with higher rates of photoelectric absorption followed by fluorescence compared to scattering tend to decrease the effect of the environmental interferences over the entire spectrum. The origin of the environmental interferences was estimated to be interference with the detector shield and/or X-ray tube collimator, which are particular design features of the device used. Their effect on contributing to the environmental interferences was evaluated by experiment for the detector shield and simulation for the X-ray tube collimator. As the detector shield was found to only contribute to a decrease in overall spectrum intensity, the major contributor to the environmental interferences was determined to be the collimator. It is believed that the results of this study will help to confirm that Monte Carlo simulation can properly provide calibration data for using HH-XRF on nuclear materials for which reference materials are hard to obtain.

The use of metal nitrate-modified amorphous nano silica for synthesizing solid amine CO2 adsorbents with resistance to urea linkage formation

The formation of urea linkages is a limitation to the application of solid amine CO2 adsorbents. Therefore, the development of solid amine adsorbents with resistance to urea linkage formation has attracted much interest over the last 5 years. In this study, we developed a facile method for synthesizing solid amine adsorbents with effective resistance to urea linkage formation. For the first time, metal nitrates were used to modify amorphous nano SiO2 to support polyethyleneimine (PEI). Three metal nitrates were investigated: aluminum, magnesium, and zinc nitrates. A series of adsorbents were prepared by controlling the mass ratios of metal nitrates and nano SiO2. After 50 cycles of adsorption–desorption tests, adsorbing at 75 °C under 15 % CO2 balanced with N2 and desorbing at 130 °C under pure CO2, Al-20%@SiO2-PEI, Al-15%@SiO2-PEI, Al-10%@SiO2-PEI, Zn-10%@SiO2-PEI, and Mg-10%@SiO2-PEI lost only 2.6 %, 4.0 %, 5.2 %, 15.9 %, and 28.8 % of their original CO2 adsorption capacities, respectively. However, SiO2-PEI, calcined SiO2-PEI, and Al-5%@SiO2-PEI lost 42.9 %, 48.6 %, and 49.6 %, respectively. By combining the infrared spectra of all the adsorbents through cyclic adsorption–desorption tests, inhibitory effects on urea linkage formation were proven for Al-20%@SiO2-PEI, Al-15%@SiO2-PEI, Zn-10%@SiO2-PEI, and Mg-10%@SiO2-PEI, and especially for Al-10%@SiO2-PEI. Through a relatively comprehensive analysis, we found that a desirable amount of metal nitrates could modify nano SiO2 samples and their corresponding adsorbents possessed a stronger H2O binding ability at 130 °C. The retained H2O could act as an inhibiting agent for the inhibition of urea linkage formation.

Синтез катализаторов Al – Fe/SiO2 и Al – Co/SiO2 твёрдофазным методом

Powders of catalysts from aluminides Fe and Co on a SiO2 support (33.3 wt. %) were obtained by mechano-thermal synthesis. The formation of large powder fractions (> 100 μm) was experimentally established. The fractions of these fractions for Fe – Al – SiO2 and Co – Al – SiO2 respectively amounted to ~ 43 % and ~ 55 %, which is a positive result for further catalytic studies. After annealing the powders at 700 and 900 °C in vacuum, the SiO2 support and compounds: Co27Al73 (close in composition to CoAl3, Co4Al13 type intermetallic compounds), Fe3Al intermetallic compound with iron silicide type Fe0.9Si0.1 and compound Al0,3Fe3Si0.7 in small volumes. On the synthesis of cobalt aluminides, a conclusion has been made about more efficient annealing at 900 °C than at 700 °C. For Fe – Al – SiO2 powders, it is advisable to anneal in the temperature range 700 – 750 °C with the assumption that the SiO2 support influences the thermosynthesis of iron aluminides. An experimental analysis of the morphology and elemental composition of the surface of the obtained samples is presented. It was found that the catalyst powders have medium sphericity and angularity. Fe – Al – SiO2 powders have a more developed surface than Co – Al – SiO2. Lower intermetallics are predominantly formed on the surface of the Co – Al – SiO2 sample. The correction of the mechanical alloying modes by means of the fragmentation of the process, changes in the intensity of its parameters, and various annealing conditions for Co – Al – SiO2 and Fe – Al – SiO2 are proposed.

High performance DUV-visible 4H-SiC-based multilayered SnS2 dual-mode photodetectors

Enhanced photocurrent density (0.1 μA μm−2), higher responsivity (>104 A W−1) and faster response time under 325 nm laser can be achieved by our fabricated SnS2/SiC photodetector towards a SiO2 sample.

Silicon Ultrathin Oxide (4.2 nm)–Polysilicon Structures Resistant to Field Damages

The results of investigations of silicon–ultrathin oxide (42 A)–polysilicon structures resistant to field damages are presented. It is found that the total charge exchange of localized electronic states and minority charge carriers concentrated at the substrate–insulator interface, which occurs with a change in the field voltage, is close to the same characteristic of structures with an oxide thickness of 37 A. The current flowing through SiO2 increases with voltage much stronger in the enrichment state of the semiconductor than in its depletion state. Moreover, the asymmetry of the I–V characteristics with respect to the polarity of the voltage drop across the insulator in SiO2 samples with a thickness of 42 A is more pronounced than in structures with an oxide of 37 A. An explanation for this asymmetry is possible, if the potential relief in the insulator has a peak, which is significantly shifted to the oxide–polysilicon interface, and the potential on the branch on the semiconductor side significantly decreases towards the contact with the substrate.

Micropalaeontological and Geochemical Evidence of the Late Jurassic Radiolarians Cherts of Naga Ophiolite Hill, Nagaland, Northeast-India

We analyzed the radiolarian assemblages (pelagic sediments) and geochemical studies of 15 samples collected from Meluri district Nagaland, Naga Hills Ophiolite belt (NHO) and it consists of the Flysch Naga-Arakan-Yoma trough beyond the Indo-Myanmar border. It reflects one of the many components of the Himalayan Orogenic systems of Tethyan oceanic crust discovered in Nagaland at Meluri district of India and they have very well-preserved studies and can be identified to Upper Jurassic (Kimmeridgian-mid-Tithonian). As well as a continuous sequence of Kimmeridgian-mid-Tithonian, five radiolarian assemblages have been identified in this study. This is so far the first recovery of pelagic sediment assemblages (Radiolarians) from the Naga Hills Ophiolite complex. Samples of Naga Hills Ophiolite belts fell in the Sublitharenite, Litharenite, and Fe-shale Fe-sand area, and the A-CN-K diagram indicates that these sediments in the source region were exposed deep to moderate weathering conditions. In the discriminant plot, the Naga Hill-Ophiolite-Chert samples occupy the field of origin of the sediment quartzose, and the log (K2O/Na2O) versus SiO2 samples fall into the active continental marginal field, and only one sample falls into an island arch, suggesting that the tectonic framework of the Naga Hills-Chert samples was deposited in the active continental margin and the diagrams K2O/Al2O3 and MgO/Al2O3 illustrated the tectonic setting of the marine environment from Naga Hill Ophiolite Chert. Such findings have been consistent with the current geology of Naga Hills in the province of Nagaland.

Chemical looping gasification of high nitrogen wood waste using a copper slag oxygen carrier modified by alkali and alkaline earth metals

Chemical looping gasification (CLG) can achieve clean and highly efficient use of high nitrogen wood waste (HNWW). In this work, the feasibility of CLG of HNWW is explored using a modified copper slag (CS1100) as an oxygen carrier (OC). The CS1100 sample modified by alkali and alkaline earth metals (AAEMs) was first prepared, and then the reactivity of different OCs was evaluated. The K-modified CS1100 (K-CS) sample showed the highest reactivity due to the formation of KFe2O4. Lattice oxygen was beneficial to char conversion, evidently promoting HNWW conversion. The K-CS sample showed the highest carbon conversion (74.65%) and valid gas yield (641 mL/g), followed by the Ca-CS and Na-CS samples, which exhibited a much higher carbon conversion than the inert SiO2 sample (40.45% and 327 mL/g). The K-CS sample can evidently promote the release of N and the subsequent oxidation of nitrogen-containing pollutants (i.e., NH3 and HCN), thus lowering the emissions of nitrogen pollutants. Char-N accounts for 22.54% of N during pyrolysis; however, char-N only accounts for 2.27% of N during CLG. Additionally, compared to pyrolysis, the emissions of nitrogen-containing pollutants decreased by approximately 20% in CLG. The Protein-N (N-P) and Urea-N (N-U) were decomposed to form Pyrrole-N (N-5) and Pyridine-N (N-6); and then formed Protonated pyridine N (N-Q) and Pyridine N-oxide (N-X) during thermal conversion of HNWW. Additionally, more N-X and N-6 remained in the residual char during CLG than during pyrolysis because of the presence of active OC. KFe2O4 acted as a catalyst rather than an oxidizer during CLG, and the K-CS sample can act as an OC for recycling.

Migration, Crystallization and Dissolution Changes of Salt Solution with Color Rendering Property in Porous Quartz Materials.

In order to visually display the migration and crystallization process of salt solution in porous cultural relics, copper sulfate solution with color rendering property was selected to record the migration, crystallization and resolution of salt solution in simulated SiO2 samples under different environmental conditions in real time through high-resolution recording system, scanning electron microscope system, salt phase X-ray diffraction system, and so on. The results showed the migration of salt solution in porous samples was related to the structural characteristics of the porous samples, the migration rate of salt solution, the evaporation rate and the change frequency of crystallization–resolution, etc., in which the large pore size of the sample, the higher the concentration and the faster migration and evaporation rate of salt solution, the greater the change rate of the brine accumulation zone or salt crystallization zone in the different porous samples. During the humidification–drying cycles of rainfall, the higher the cycle frequency of humidification–drying was, the higher the drying temperature was, the more frequent the crystallization-analysis change of salt in the salt-bearing sample was, and the more extensive the distribution of salt crystal zone was. This is the first time to visualize the salt belt by simulating the changing process of a salt solution with a color rendering property in porous samples. This has scientific theoretical guidance for the study of the migration–crystallization changes of soluble salts contained in porous silicate cultural relics. The visibility analysis results of multilayer salt crystal belts can also provide the preliminary basis for further effective desalination of salt bearing cultural relics.

The Judd Ofelt Spectroscopic analysis for Ho3+ doped with SiO2

Holmium ions Ho3+ Doped with Silicon dioxide was synthesis with help of wet chemical process. Techniques such as UV- Visible spectroscopy and fluorescence spectroscopy were used to investigate the spectroscopic properties of of Ho3+:SiO2 sample. The Judd-Ofelt theory is used to achieve of the spectroscopic properties to prepared sample and calculates the three Judd-Ofeltt of parameters; Ω2, Ω4 and Ω6. From the obtained parameters, the A(J;J’), τrad and β J → J are calculated. Depending on the suitable value of A(J;J’), τrad and β J → J it could suggests to use Ho:SiO2 as Laser active medium.

Microstructure and Magnetic Properties of La-Ca-Co Substituted M-Type Sr-Hexaferrites with Controlled Si Diffusion

La-Ca-Co substituted M-type Sr-hexaferrites (Sr0.3Ca0.4La0.3Fe9.8Co0.2O19-δ) were prepared by a solid-state reaction using two different procedures, where the SiO2 additive was mixed either before calcination (pre-Si) or after calcination (post-Si). At the same sintering temperature, smaller cell volumes and reduced saturation magnetization (Ms) values were obtained for samples processed with the pre-Si method than those with the post-Si method. This implied that the pre-Si method resulted in a greater degree of Si substitution into the M-type lattice and increased Fe extrusion out of the lattice. The grain growth behavior was controlled by the SiO2 amount and sintering temperature. It was found that abnormal grains occur with a bimodal distribution in the 0.5 wt% SiO2 samples sintered at 1240 °C, due to the increased critical driving force for growth caused by an increased amount of SiO2 addition. The Ms and coercivity values were altered with the control of Si diffusion and abnormal grain growth. The control of the additive diffusion behavior is one of the important keys in the material design under same materials compositions.