Phase equilibria in the system CaO-CoO-SiO2and Gibbs energies of formation of the quaternary oxides CaCoSi2O6, Ca2CoSi2O7, and CaCoSiO4

Mukhopadhyay, Sukanya; Jacob, Κ. T.

doi:10.2138/am-1996-7-818

Cited by 16 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The thermodynamic behavior of high temperature rock-salt type Ca 1 À x Co x O solid solution has been studied by several authors by direct determination of miscibility limits by phase equilibration studies [12,16,17] and by measuring the respective component activities in solid electrolyte galvanic cells [23,24]. Although only the data reported by Jakob et al [16] and Mukhopadhyay and Jakob [17] were used to evaluate the temperature dependent R-K parameters for excess Gibbs energy (Eq.…”

Section: Thermodynamic Datamentioning

confidence: 99%

“…Although only the data reported by Jakob et al [16] and Mukhopadhyay and Jakob [17] were used to evaluate the temperature dependent R-K parameters for excess Gibbs energy (Eq. (2), Table 3), the agreement between the other experiments and the miscibility gap calculated using the optimized parameter values shown in Fig.…”

Section: Thermodynamic Datamentioning

confidence: 99%

“…The total oxygen content 9 þ d Table 3) with various experimental data ( , [16]; , [17]; , [12], , [25]; , [23]; , [24]). calculated for the ratio Ca/Co¼3/3.9 (ideal with respect to the used CEF mode) is plotted as a function of temperature and partial pressure of oxygen (Fig.…”

Section: Phase Diagrammentioning

confidence: 99%

“…In this study we thus focus on the assessment of the Ca-Co-O phase diagram based on both our and literature experimental data [12][13][14][15][16][17]. Since the system under study should be considered as closed for Ca and Co while open for oxygen which is exchanged with the surrounding atmosphere and whose content is determined and controlled by the oxygen activity in surroundings, the phase diagram is represented by means of three experimentally adjustable predictors -temperature, cation composition and oxygen activity (partial pressure).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Phase equilibria in Ca–Co–O system

Sedmidubský

Jakeš

Jankovský

et al. 2012

Journal of Solid State Chemistry

104

View full text Add to dashboard Cite

Section: Thermodynamic Datamentioning

confidence: 99%

Section: Thermodynamic Datamentioning

confidence: 99%

Section: Phase Diagrammentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Phase equilibria in Ca–Co–O system

Sedmidubský

Jakeš

Jankovský

et al. 2012

Journal of Solid State Chemistry

104

View full text Add to dashboard Cite

“…Therefore, the synthesized pigments must exhibit excellent thermal and chemical stability. There have been researches into the synthesis, phase formation, and thermal stability in Co olivines and related compounds such as CaCoSi 2 O 6 , Ca 2 CoSi 2 O 7 , and CaCoSiO 4 [ 1 , 2 , 3 ]. Forsterite [ 4 , 5 ], with the chemical formula Mg 2 SiO 4 , is a crystalline magnesium silicate and seems to be usable as the ceramic pigment due to its fabulous refractoriness.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterizations of (CoxMg(2−x))SiO4 Forsterite Ceramic Pigments from Mirror Waste

et al. 2018

View full text Add to dashboard Cite

Ceramic pigments have been widely used in a variety of industries because of their excellent properties, such as high thermal stability, low-cost productions, and simple manufacturing processes. Re-use of mirror waste, which consists of silicon dioxide greater than 70%, is a method that can reduce raw materials cost. In this work, ceramic pigment with forsterite structure, Mg2SiO4, was synthesized via conventional solid state reaction by using mirror waste as a precursor. Solid solutions of Co-doped forsterite pigment, CoxMg(2−x)SiO4 where x = 0.02–1.6, were calcined at 1000 °C for 2 h. The calcined powders were characterized by X-ray diffraction technique (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis spectrophotometer, and color measurement (CIEL*a*b*). XRD results confirmed that forsterite phase was found as a main phase in the ceramic powder. However, the forsterite phase decreased with increased concentration of Co to x = 0.8–1.6. This could be because of the solubility limit of Co in solid solution. In addition, the use of mirror waste as a raw material was able to reduce calcination temperature compared to the use of oxide reagents. Color measurements or CIEL*a*b* color space of forsterite pigments were located in red-blue quadrant for Co-doped pigment.

show abstract

Phase Equilibria in the System Al2O3-CaO-CoO and Gibbs Energy of Formation of Ca3CoAl4O10

Jacob

Shekhar

Kale

2008

J. Phase Equilib. Diffus.

Self Cite

View full text Add to dashboard Cite

An isothermal section of the system Al 2 O 3 -CaO-CoO at 1500 K has been established by equilibrating 22 samples of different compositions at high temperature and phase identification by optical and scanning electron microscopy, X-ray diffraction, and energy dispersive spectroscopy after quenching to room temperature. Only one quaternary oxide, Ca 3 CoAl 4 O 10 , was identified inside the ternary triangle. Based on the phase relations, a solid-state electrochemical cell was designed to measure the Gibbs energy of formation of Ca 3 CoAl 4 O 10 in the temperature range from 1150 to 1500 K. Calcia-stabilized zirconia was used as the solid electrolyte and a mixture of Co + CoO as the reference electrode. The cell can be represented as: ð-ÞPt; CaAl 2 O 4 + Ca 12 Al 14 O 33 + Ca 3 CoAl 4 O 10 + Co//(CaO)ZrO 2 //CoO + Co; Pt ð + Þ: From the emf of the cell, the standard Gibbs energy change for the Ca 3 CoAl 4 O 10 formation reaction, CoO + 3/5CaAl 2 O 4 + 1/5Ca 12 Al 14 O 33 fi Ca 3 CoAl 4 O 10 , is obtained as a function of temperature: DG o r /J mol 21 (±50) = 22673 + 0.289 (T/K). The standard Gibbs energy of formation of Ca 3 CoAl 4 O 10 from its component binary oxides, Al 2 O 3 , CaO, and CoO is derived as a function of temperature. The standard entropy and enthalpy of formation of Ca 3 CoAl 4 O 10 at 298.15 K are evaluated. Chemical potential diagrams for the system Al 2 O 3 -CaO-CoO at 1500 K are presented based on the results of this study and auxiliary information from the literature.

show abstract

Phase equilibria in the system CaO-CoO-SiO₂and Gibbs energies of formation of the quaternary oxides CaCoSi₂O₆, Ca₂CoSi₂O₇, and CaCoSiO₄

Cited by 16 publications

References 0 publications

Phase equilibria in Ca–Co–O system

Phase equilibria in Ca–Co–O system

Synthesis and Characterizations of (CoxMg(2−x))SiO4 Forsterite Ceramic Pigments from Mirror Waste

Phase Equilibria in the System Al2O3-CaO-CoO and Gibbs Energy of Formation of Ca3CoAl4O10

Contact Info

Product

Resources

About