Silicate Formation Research Articles

Low Hysteresis Vanadium Dioxide Integrated on Silicon Using Complementary Metal‐Oxide Semiconductor Compatible Oxide Buffer Layer

VO2 undergoes a metal‐insulator transition (MIT) at ≈70 °C, which induces large variations in its electrical and wavelength‐dependent optical properties. These features make VO2 a highly sought‐after compound for optical, thermal, and neuromorphic applications. To foster the development of VO2‐based devices for the microelectronic industry, it is also imperative to integrate VO2 on silicon. However, high lattice mismatch and the formation of silicates at the interface between VO2 and Si degrade the quality and functionality of VO2 films. Moreover, VO2's polymorphic nature and stable VO phases pose integration issues. To address these challenges, the MIT of VO2 thin films integrated on Si with a complementary metal‐oxide semiconductor‐compatible HfxZr1−xO2 (HZO) buffer layer is investigated. Using in situ high‐resolution X‐ray diffraction and synchrotron far‐infrared spectroscopy, combined with multiscale atomic and electronic structure characterizations, it is demonstrated that VO2 on the HZO buffer layer exhibits an unusually low thermal hysteresis of ≈4 °C. In these results, the influence of strain on M2 phase nucleation, which controls the hysteresis, is unraveled. Notably, the rate of phase transition is symmetric and does not change for the heating and cooling cycles, implying no incorporation of defects during cycling, and highlighting the potential of an HZO buffer layer for reliable operation of VO2‐based devices.

Introducing Y2O3 passivation layer for utilizing TiSiN electrode on ZrO2-based metal-insulator-metal capacitor applications

This study investigates the degradation and improvement of the dielectric properties of ZrO2-based metal-insulator-metal (MIM) capacitors using TiSiN electrodes. As dynamic random-access memory (DRAM) design rules scale down, the mechanical properties of TiSiN electrodes provide advantages over conventional TiN, but also introduce challenges due to Si diffusion into ZrO2 films, forming low-dielectric constant (k) Zr-silicate and defect-related dielectric degradation. We evaluate the dielectric properties of ZrO2 films on TiSiN electrodes and identify significant reductions in the dielectric constant and an increase in DC and AC non-linearity due to Zr-silicate formation. To mitigate these problems, a Y2O3 passivation layer is introduced between the TiSiN electrode and ZrO2 dielectric film. Physical and chemical analyses, including X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), confirm that Y2O3 passivation effectively suppresses Si diffusion, preventing formation of Zr silicate, and preserving the high-k tetragonal phase of ZrO2. Electrical measurements show that the Y2O3 layer significantly improves the dielectric constant and reduces non-linearity effects. Notably, even at a reduced ZrO2 thickness of 4 nm, a relatively high k value is maintained with Y2O3 passivation. This study concludes that the Y2O3 passivation layer is indispensable for maintaining high dielectric performance in ZrO2-based MIM capacitors with TiSiN electrodes, ensuring stability and efficiency in advanced DRAM applications.

Impact of Inverse Manganese Promotion on Silica-Supported Cobalt Catalysts for Long-Chain Hydrocarbons via Fischer–Tropsch Synthesis

One of the challenges in Fischer–Tropsch synthesis (FTS) is the high reduction temperatures, which cause sintering and the formation of silicates. These lead to pore blockages and the coverage of active metals, particularly in conventional catalyst promotion. To address the challenge, this article investigates the effects of the preparation method, specifically the inverse promotion of SiO2-supported Co catalysts with manganese (Mn), and their reduction in H2 for FTS. The catalysts were prepared using stepwise incipient wetness impregnation of a cobalt nitrate precursor into a promoted silica support. The properties of the catalysts were characterized using XRD, XPS, TPR, and BET techniques. The structure–performance relationship of the inversely promoted catalysts in FTS was studied using a fixed-bed reactor to obtain the best performing catalysts for heavy hydrocarbons (C5+). XRD and XPS results indicated that Co3O4 is the dominant cobalt phase in oxidized catalysts. It was found that with increase in Mn loading, the reduction temperature increased in the following sequence 10%Co/SiO2 < 10%Co/0.25%Mn-SiO2 < 10%Co/0.5%Mn-SiO2 < 10%Co/3.0%Mn-SiO2. The catalyst with the lowest Mn loading, 10%Co/0.25%Mn-SiO2, exhibited higher C5+ selectivity, which can be attributed to less MSI and higher reducibility. This catalyst showed the lowest CH4 selectivity possibly due to lower H2 uptake and higher CO chemisorption.

Influence of potassium addition on phosphorus availability and heavy metals immobility of biochar derived from swine manure

Pyrolysis of animal manure at high temperature is necessary to effectively immobilize heavy metals, while the available phosphorus (P) level in biochar is relatively low, rendering it unsuitable for use as fertilizer. In this study, the pretreatment of swine manure with different potassium (K) sources (KOH, K2CO3, CH3COOK and C6H5K3O7) was conducted to produce a biochar with enhanced P availability and heavy metals immobility. The addition of all K compounds lowered the peak temperature of decomposition of cellulose in swine manure. The percentage of ammonium citrate and formic acid extractable P in biochar increased with K addition compared to undoped biochar, with CH3COOK and C6H5K3O7 showing greater effectiveness than KOH and K2CO3, however, water- extractable P did not exhibit significant changes. Additionally, the available and dissolved Si increased due to the doping of K, with KOH and K2CO3 having a stronger effect than CH3COOK and C6H5K3O7. X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed that K addition led to the formation of soluble CaKPO4 and silicate. In addition, the incorporation of K promoted the transformation of labile copper (Cu) and znic (Zn) into the stable fraction while simultaneously reducing their environmental risk. Our study suggest that the co-pyrolysis of swine manure and organic K represents an effective and valuable method for producing biochar with optimized P availability and heavy metals immobility.

Oxidation mechanism of the Si-X (X=HfO2, Yb2O3 or HfO2+Yb2O3) composite systems in air and water vapor at 1300 ℃

The formation rate of SiO2 during oxidation of Si bond layer is a key issue to determine the lifetime of environmental barrier coatings. The oxidation kinetics and mechanism of Si and Si-X (X=HfO2, Yb2O3 or HfO2+Yb2O3) composite systems were investigated systematically. The thickness of the SiO2 layer was greatly reduced by the dynamic formation of silicates (HfSiO4, Yb2SiO5 and Yb2Si2O7) in air and water vapor, benefiting for long-term servicing. However, the addition of HfO2 promoted the oxidation of Si with an increased total SiO2 thickness, while that of Yb2O3 not. These results provide a guidance for the design of next generation bond layers.

Efficient CoCu/SiO2 Catalyst Derived from Co(Cu) Silicate for Aqueous‐Phase Furfural Hydrogenation

AbstractConverting the abundant biomass resources in nature into fine chemicals can not only reduce carbon emissions but also effectively deal with the depletion of fossil energy, which is of strategic significance for sustainable development. In this paper, by optimizing the content of bimetallic components, highly active co‐doped Co1Cu3 bimetallic silicate was designed and synthesized. After reduction, a highly dispersed and stable Co1Cu3/SiO2 catalyst was obtained, which was used to catalyze the aqueous phase hydrogenation of furfural (FFR) to cyclopentanone (CPO). Compared with the traditional supported catalyst, the Co1Cu3/SiO2‐ammonia evaporation (AE)‐300 catalyst prepared by AE has the best performance. Under the optimal reaction conditions, the conversion of FFR was as high as 95.1 % and the selectivity of CPO was 88.6 %. This high activity can be attributed to the formation of highly dispersed and uniform metal active sites with low content of Co. At the same time, the formation of flocculent silicate enhances the synergism between CoCu and SiO2 support and increases the specific surface area of the catalyst. In addition, the experimental results show that the reaction carbon balance will be destroyed with the high concentration of FFR solution.

Theoretical Rotational and Vibrational Spectral Data for the Hypermagnesium Oxide Species Mg2O and Mg2O.

While magnesium is astronomically observed in small molecules, it largely serves as a contributor to silicate grains, though how these grains form is not well-understood. The smallest hypermagnesium oxide compounds (Mg O/Mg O ) may play a role in silicate formation, but little vibrational reference data exist. As such, anharmonic spectroscopic data are computed for Mg O, Mg O, and Mg O using quartic force fields (QFFs). Explicitly-correlated coupled-cluster QFFs for the neutral species perform well, implying that full multireference treatment may not be necessary for such systems if enough electron correlation is included. Equation-of-motion ionization potential (EOMIP) methods for Mg O QFFs circumvent previous symmetry breaking issues even in explicitly-correlated coupled-cluster results, motivating the need for EOMIP treatments at minimum for such systems. All three species are found to have high-intensity vibrational frequencies. Even so, the highly intense frequency ( Mg O: 894.7 cm-1/11.18 μm; Mg O: 915.0 cm-1/10.91 μm) for either neutral state may be astronomically obscured by the polycyclic aromatic hydrocarbon 11.2 μm band. Mg O may be less susceptible to such obfuscation, and its intensity is computed to be a massive 4793 km mol-1.

Cost-effective microbial induced ZnO synthesis for building material: Antibacterial, photocatalytic and mechanical characteristics

Utilization of effective and economical nanoparticles/nanocomposite materials in civil engineering is still remaining a significant challenge in current research arena. In this study, microbial-induced precipitation was formulated for integration of white cement mortar to enhance efficiency and evaluate its potential applications in antibacterial and photocatalytic degradation of methylene blue. Hexagonal wurtzite structure of synthesized ZnO exhibited high crystallinity with significant contribution of hydration product after 28days analysis. Morphology of produced material showed less homogeneity with high densification and morphology altered from needles-like structure to tube with the integration of adsorbent ratio from ZnO-0 to 2.5, presented all the required chemical components in EDXS analysis. The water absorption rate in sample slurry of ZnO-2.5 exhibited significant reduction of 52.75 % compared to baseline water absorption rate of 12.71 % in commercial ZnO and contact angle was noted higher as 89.54°, which indicates hydrophilic character of material. The highest compressive strength of sample ZnO-2.5 was noted 508.89 kgf/cm2 in 28days of wet curing method, indicated the effective gel formation of calcium silicate in samples. Maximum methylene blue dye degradation recorded 79.95 % in case of using ZnO-2.5, which showed another influential character with excellent efficiency. In addition, prepared sample has shown almost complete bactericidal efficiency under simulated sunlight. Compared to commercial white cement mortar, biological white cement mortar can save NT$149,531 per cubic meter at industrial scale. Therefore, results indicate that microbial-induced zinc precipitation incorporated using hydrothermal preparation of biological white cement mortar improves the surface properties for applications and reduces its cost of study.

A novel strategy to improve the corrosion resistance of SiCf/SiC composites in high-temperature combustion environments by cooperation of self-healing SiBCN and high-stability Yb2Si2O7

How to improve the resistance to water-oxygen-salt corrosion of SiCf/SiC composites is vital to their long-term service in the advanced aero-engines or gas turbines. SiCf/SiC-SiBCN-Yb2Si2O7 (SSY) self-healing composites were exposed to combustion environments at 1200–1350 °C for a long time up to 100 h. The dissolution of solid Yb2Si2O7 into low-viscosity glassy oxides derived mainly from oxidation of SiBCN leads to the formation of stable Yb2Si2O7-contianing multi-phase silicate which can inhibit the diffusion of corrosive media and alleviate corrosive damage of composites. After corrosion in H2O/O2/Na2SO4 at 1200 °C and 1350 °C, the strength retention rates of SSY are 96 % and 88 %, respectively, (6.4 ± 0.9)% higher than those of SiCf/SiC-SiBCN (SS), due to the good cooperative protective effect of SiBCN-Yb2Si2O7. However, the insufficient dissolution of Yb2Si2O7 causes the formation of plenty of solid/liquid interfaces conductive to the diffusion of corrosive media in H2O/O2 at 1200 °C and 1350 °C. As a result, the retention rates of flexural strengths of SSY are 100 % and 91 %, respectively, (2.5 ± 0.5)% lower than those of SS.

Composition features of the Upper Carboniferous-Lower Permian rocks of the Losinoostrov Fm. and the role of extrabasin sources in their formation (Subpolar Urals)

Research subject. The Upper Carboniferous-Lower Permian rocks of the Losinoostrov Formation of the Belsk-Eletsk structural-formational zone, exposed on the left bank of the Kozhim river, near the mouth of the stream Northnichael of the western slope of the Subpolar Urals. Methods. Optical and electron microscopic methods (including cathodoluminescence), chemical silicate, carbonate and X-ray diffraction analyses. Results and conclusions. The studied rocks are assigned to three main groups: mixtolites (rocks of mixed composition), carbonatoliths, and silicytolites with varieties. Mixtoliths consist of three and four main components: carbonate, silty, argillaceous and siliceous. The variable ratio of rock-forming components of mixtolites was clearly reflected in the discriminative modular diagram. Here, fields of predominantly siliceous and silty mixolites (cluster I), predominantly argillaceous (cluster III), as well as transitional mixolites (cluster II) are identified. Relatively pure and silty-argillaceous-siliceous limestones were distinguished among carbonatoliths. According to the formed elements, pure limestones are divided into bioclastic and peloid-micritic. Silicytolites are represented by (1) radiolarites and radiolarian spongoliths; (2) silty-argillaceous silicytolites and (3) cherts (secondary siliceous formations). The established quantitative ratios of rock-forming components showed that more than half of the studied mixtoliths are composed mainly of the material of extrabasinal origin. Relatively high contents of extrabasinal fine material in carbonatoliths indicate a periodic decrement of the hydrodynamic regime during the accumulation of the upper part of the formation. The studied deposits were probably formed in distal and proximal ramp settings.

Iron isotope fractionation between metal and silicate during core-mantle differentiation in rocky bodies

Fe isotope variations in rocky bodies reveal fundamental information about planetary evolution. However, experimental results have come to contradictory conclusions on the equilibrium Fe isotope fractionation between metal and silicate during core-mantle differentiation. Many different processes, including evaporation, core formation, partial melting and disproportion of mantle silicate, have been consequently proposed to explain the observed Fe isotope variations in rocky solar system bodies. Here we perform ab initio molecular dynamics simulations and find that the anharmonicity in iron strongly decreases the force constant of Fe at low pressures (<∼50 GPa), which even reverses the equilibrium Fe isotope fractionation between metal and silicate. We conclude that pyrolitic melt is always enriched in heavy Fe isotopes relative to liquid Fe-alloys, no matter what pressure. Therefore core-mantle differentiation will play a significant role in explaining the heavy Fe isotope compositions of the mantles of some rocky bodies (e.g., Earth, the ureilite parent body, and possibly the asteroid Vesta). As all previously proposed processes for Fe isotope fractionation can only enrich the mantle-derived rocks in heavy Fe isotopes, the near/sub-chondritic Fe isotope signatures of Mars and the aubrite parent body thus imply that iron sulfide enriched in light Fe isotopes may significantly contribute to the iron components of those meteoritic samples.

Alkali Silicates Codoped with NIR-Emitting RE (Nd3+ and Yb3+) Ions for Thermometry Applications.

In the present study, the synthesis of BaSrSiO4 co-doped Yb3+ and Nd3+ nanophosphors (NPs) was successfully achieved through the conventional sol-gel method, as confirmed by X-ray diffraction and SEM analysis, verifying the formation of pure NPs. The FTIR and Raman spectra analysis confirm the formation of silicates, as different modes and vibrations of Si-O and Si-O-Si were seen at 800-1000cm-1. The energy transfer (ET) mechanism between Nd3+ and Yb3+ ions was seen as the emission spectra showed a rise in intensity of one over another. PLE emission spectra showed transitions at 2F7/2-2F5/2 for Yb3+ and from 4F3/2 to (4I9/2, 4I11/2, and 4I13/2) for Nd3+ when excited at 785nm. All the samples record low activation energy, which shows that the rate of reaction will be higher in all the samples, and it will be highest for 1mol% Nd3+ and 1mol% Yb3+. An increasing value of τ was seen with increasing Yb3+ concentration, which confirms the increase in the population of trap centers. The positron annihilation lifetime (PAL) curve showed that 1mol% Yb3+ and 2mol Nd3+ have single vacancies or shallower positron traps, whereas 3mol% Yb3+ and 2mol% Nd3+ have larger defects like surface oxygen vacancy clusters. The other two samples have balance vacancies, which makes them best for thermometry applications. The fluorescence intensity ratio (FIR) was calculated to get sensitivity for thermometry application. 2.13% K-1 sensitivity achieved at 303-333K temperature.

Supernova Ejecta with Crystalline Silicate Dust in the Supernova Remnant MSH 15–52

IRAS 15099-5856 in the young supernova remnant (SNR) MSH 15−52 is the first and only SNR-associated object with crystalline silicate dust detected so far, although its nature and the origin of the crystalline silicate are still unclear. In this paper, we present high-resolution mid-infrared (MIR) imaging observations of the bright central compact source IRS1 of IRAS 15099-5856 to study the spatial distributions of gas and dust and the analysis of its Spitzer MIR spectrum to explore the origin of IRS1. The MIR images obtained with the T-ReCS attached on the Gemini South telescope show a complicated, inhomogeneous morphology of IRS1 with bright clumps and diffuse emission in [Ne ii] 12.81 μm and Qa 18.30 μm, which confirms that IRS1 is an extended source externally heated by the nearby O star Muzzio 10, a candidate for the binary companion of the progenitor star. The Spitzer MIR spectrum reveals several ionic emission lines including a strong [Ne ii] 12.81 μm line, but no hydrogen line is detected. We model the spectrum using the photoionization code Cloudy with varying elemental composition. The elemental abundance of IRS1 derived from the model is close to that of supernova (SN) ejecta with depleted hydrogen and enhanced metals, particularly neon, argon, and iron. Our results imply that IRS1 originates from the SN ejecta and suggest the possibility of the formation of crystalline silicate in newly formed SN dust.

Nuclear waste glass alteration under the influence of iron, claystone, and cementitious grout: An integral study

To prepare for the future deep geological disposal of high-level waste, the alteration of two inactive nuclear glasses was studied in the presence of claystone, iron, and cementitious grout at 50 °C for a period of 4 years. The materials were immersed together in a synthetic water representative of claystone solution composition. Blank experiments were also carried out to study the independent behaviors of iron and glass in the synthetic water. The evolution of the solutions’ chemistry was monitored. At the end of the experiments, the glass and iron, as well as the neoformed phases, were characterized. Results showed that Si, Ca, Mg, and Fe are key elements. A competition exists between the retention/integration of species into glass gels and clay-like neoformations. Magnesium tends to be leached from glasses and form Mg-silicates. It would only integrate into the gel if it was widely available in the solution. Furthermore, iron could form Fe-silicates. Whether for Mg or Fe, the formation of silicates was detrimental to the glass since it involved the creation of a silicon sink and thus the conservation of a high alteration rate. Concerning calcium, in these experiments it appeared that this species tends to be integrated/retained within the gels. In the pH conditions existing here, it seems that there is no competition with a neoformation. The specific impact of the cementitious grout was also studied, and the results showed that the presence of this material in the system had a beneficial effect on glass alteration due to a significant Si supply in the solution, enabling a reduction in the glass alteration rate.

Evaluation of baghdadite (Ca3ZrSi2O9) cements for the application as novel endodontic filling materials

ObjectivesBaghdadite (Ca3ZrSi2O9) cements of various composition have been investigated in this study regarding an application as endodontic filling materials. MethodsCements were either obtained by mixing mechanically activated baghdadite powder with water (maBag) or by subsequently substituting the ß-tricalcium phosphate (ß-TCP) component in a brushite forming calcium phosphate cement. The cements were analyzed for their mechanical performance, injectability, radiopacity, phase composition and antimicrobial properties. ResultsThe cements demonstrated sufficient mechanical performance with a compressive strength of ∼1 MPa (maBag) and 2.3 – 17.4 MPa (substituted calcium phosphate cement), good injectability > 80 % depending on the powder to liquid ratio and an intrinsic radiopacity of 1.13 – 2.05 mm aluminum equivalent. Immersion in artificial saliva proved their bioactivity by the formation of calcium phosphate and calcium silicate precipitates on the cement surface. The bacterial activity of Staphylococcus aureus cultured on the surface of the cements was found to be similar compared to clinical standard ProRoot MTA cement or even reduced by a factor of 3 for Streptococcus mutans. SignificanceIn combination with their antibacterial properties, baghdadite cements are thought to have the potential to fulfil the clinical requirements for endodontic filling materials.

Solidification/stabilization of lead-contaminated soil using alkali-activated volcanic ash

The bioaccumulation of lead in soil poses a significant human health risk. The solidification/stabilization (S/S) technique, employing binders like Portland cement or lime, is a common method for remediating lead-contaminated soil. However, cement production has adverse environmental impacts, prompting the exploration of eco-friendly alternatives like alkali-activated materials (AAMs). This study assesses AAM efficacy in the S/S of lead-contaminated soil. The effects of several factors, including varying amounts of volcanic ash (VA), lead concentration, curing temperatures, and curing times are investigated. Unconfined compressive strength (UCS), toxicity characteristic leaching procedure test (TCLP), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and field emission scanning electron microscope-energy-dispersive spectroscopy-mapping analyses (FESEM/EDS/mapping) analyses are used to study the specimens. The findings indicated a substantial increase in the UCS of lead-contaminated soil treated with 15% VA (under oven curing (OC) conditions), and 10% VA (under ambient curing (AC) conditions) exhibited remarkable increases of up to 600% and 458%, respectively. Moreover, the leaching of Pb2+ ions from samples contaminated with 10,000 mg/kg (under OC conditions) and 2500 mg/kg (under AC conditions) experienced significant reductions of 87% (from 135.14 to 13.36 ppm) and 91% (from 26.32 to 2.21 ppm), respectively. The S/S process in these samples operated through three primary mechanisms of chemical bonding, physical encapsulation, and the formation of insoluble silicate. The formation of N-A-S–H and hydroxy sodalite structures played a vital role in facilitating these mechanisms. Therefore, alkali-activated VA demonstrated excellent performance in the remediation of lead-contaminated soil.Graphical

Metal-organic decomposed lanthanum cerium oxide thin films: A study of chemical and surface properties

Lanthanum cerium oxide thin films have been deposited on n-type (100) silicon wafers using the spin coating technique. The post-deposition annealing was performed over spin-coated films. The compositional studies were conducted by performing Fourier transform infrared spectroscopy, Energy dispersive X-ray spectroscopy, and X-ray diffraction. Ellipsometry was used to determine the thickness and atomic force microscopy was performed to understand the surface morphology of the deposited thin films. The effect of rapid thermal annealing at different temperatures over the structural and chemical properties of the LaCeO2 thin films was observed. The FTIR spectra show the formation of silicates at the interface of the oxide and semiconductor, while XRD results show that the films become crystalline with increased annealing temperature. The refractive index was observed to be reduced with an increase in the annealing temperature and a minor reduction in the physical thickness as per the sample standard deviation of 0.2981[Formula: see text]nm.

Mineral Assemblages and Ore-Forming Physicochemical Conditions of the La’erma and Qiongmo Au–Se Deposits in the Western Qinling Orogen, Central China

Mineral Assemblages and Ore-Forming Physicochemical Conditions of the La’erma and Qiongmo Au–Se Deposits in the Western Qinling Orogen, Central China

Iron and silicon modified biochar for enhancing cadmium removal from water: Unveiling the crucial role of iron-induced silicon dissolution

The interaction mechanisms of silicon (Si) and active ingredient iron (Fe) on cadmium (Cd) removal are still unknown. Herein, the Fe/Si modified biochar (Fe/Si-BC) was synthesized to enhance Cd removal by pre-immersion of Fe and ball milling loading of Si. Detailed characterizations indicated that Fe and Si were successfully introduced into Fe/Si-BC, resulting in the formation of a new metallic silicate (Ca2.87Fe0.13(SiO3)2). The maximum Cd adsorption capacity of Fe/Si-BC (31.66 mg g−1) was 3.6 times and 2.5 times higher than that of Fe-BC (8.89 mg g−1) and Si-BC (11.03 mg g−1), respectively, deriving from an enhancement of Si dissolution induced by Fe introduction. The dissolved Si could capture and combine Cd to form CdSiO3 precipitation, which was strongly supported by the random forest regression and correlation between dissolved Si content and Cd adsorption capacity. This study advances the mechanistic insights into synergistic functions of Si and Fe in Cd removal.

Competitive Formation Behavior of Calcium Silicate and Calcium Ferrite in Sintering of Iron Ore Fines

Calcium silicate is the undesirable bonding phase in sinter with relatively high melting point and poor reducibility, while the formation mechanism in sinter is ambiguous. Herein, the phase transformation, phase quantification, and morphology evolution of calcium silicate and calcium ferrite in CaO‐SiO2‐Fe2O3‐Al2O3 systems under different n(Fe2O3)/n(CaO) and Al2O3 content are investigated. It is found that with the increase of n(Fe2O3)/n(CaO), the calcium ferrite phases transform from Ca2Fe2O5 (C2F) to complex calcium ferrite, and calcium silicate phases including β‐Ca2SiO4 (β‐C2S) and γ‐Ca2SiO4 (γ‐C2S) are promoted. Moreover, small amount (2%) of Al2O3 can effectively promote the content of silico‐ferrite of calcium and aluminum (SFCA) increasing from 20.95% to 46.69%, whereas inhibiting the β‐C2S from 51.79% to 42.34%. When the content of Al2O3 is over 4%, the Ca2Al(AlSiO7) phase is formed, where both the SFCA and calcium silicate are inhibited. On this base, the competitive mechanism for the formation of calcium silicate and calcium ferrite is revealed, where the Ca2+ and Si4+ are preferred to react with Fe3+ and Al3+ to form liquid phase SFCA, while the amount for β‐C2S or γ‐C2S can be decreased due to the deprivation of Ca2+ and Si4+.