The effect of Cr substitution on the structure and properties of misfit-layered Ca3Co4−xCrxO9+δ thermoelectric oxides

Prasoetsopha, Natkrita; Pinitsoontorn, Supree; Kamwanna, T.; Amornkitbamrung, Vittaya; Kurosaki, Ken; Ohishi, Yuji; Muta, Hiroaki; Yamanaka, Shinşuke

doi:10.1016/j.jallcom.2013.11.034

Cited by 40 publications

(22 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This increases the hole concentration of the system due to the charge neutrality principle. On the other hand, the average charge state of Cr is >+4.5 , higher than the charge of Co ions. In this case the concentration of hole is reduced and of the Cr‐doped sample is larger as a consequence.…”

Section: Resultsmentioning

confidence: 86%

“…a), it can be seen that all samples show metallic behaviour below 450 K approximately but the electrical behaviour changes to semiconducting characteristic above 450 K. This change in conducting behaviour was commonly observed . Doping Fe and Ga ions reduce ρ due to the lower average charge states of Fe (+2,+3) and Ga (+3) in comparison to Co (+3.5) . This increases the hole concentration of the system due to the charge neutrality principle.…”

Section: Resultsmentioning

confidence: 86%

See 1 more Smart Citation

Local structure determination of substitutional elements in Ca₃Co_4−xM_xO₉(M = Fe, Cr, Ga) using X-ray absorption spectroscopy

Pinitsoontorn

Prasoetsopha

Srepusharawoot

et al. 2014

Phys. Status Solidi A

Self Cite

View full text Add to dashboard Cite

Ca 3 Co 4 O 9 is one of the most promising thermoelectric oxide materials at high temperature. Its structure consists of two misfit layers: the CaO-CoO-CaO rocksalt-type (RS) layer and the CdI 2type CoO 2 layer. In this paper, we reported the synthesis of single phase Ca 3 Co 4Àx M x O 9 (where M ¼ Fe, Cr, and Ga). Thermoelectric measurements showed the variation of thermoelectric properties depending on the charge state of the substitutional elements. We showed the direct evidence for the location of the substitutional elements in the system using an X-ray absorption spectroscopy technique. The extended X-ray absorption fine structure spectra were fitted with the models. Also, the X-ray absorption near edge structure spectra were compared with the simulated spectra from the first principle calculation. The data analysis show that for Fe and Cr substitution, the Fe and Cr atoms are more likely to be located in the RS layer rather than in the CoO 2 as presumed previously. For the Ga case, Ga atoms accommodate both sites; still the majority stays in the RS layer. This is supported by the calculation of the total energy of the system, which showed that the total energy is lower when the substituted elements were located in the RS layer.

show abstract

Section: Resultsmentioning

confidence: 86%

Section: Resultsmentioning

confidence: 86%

Local structure determination of substitutional elements in Ca₃Co_4−xM_xO₉(M = Fe, Cr, Ga) using X-ray absorption spectroscopy

Pinitsoontorn

Prasoetsopha

Srepusharawoot

et al. 2014

Phys. Status Solidi A

Self Cite

View full text Add to dashboard Cite

show abstract

“…Apparent density was measured using Archimedes' principle for each composition, at least for four ceramic samples, and compared to the theoretical density (4.677 g/cm 3 ) [18]. to decrease on heating [19,20], with relatively weak temperature dependence at T > 200-300 ºC, the ZT values have been estimated at higher temperatures and compared to the best up-to-date literature data.…”

Section: Methodsmentioning

confidence: 99%

Tailoring Ca3Co4O9 microstructure and performances using a transient liquid phase sintering additive

Sotelo

Costa

Ferreira

et al. 2016

Journal of the European Ceramic Society

View full text Add to dashboard Cite

“…The electrical conductivity of the Ca 3 Co 4 -x M x O 9 (M = Ti, Cr, Mn, Fe, Cu) solid solu tions is somewhat lower [5][6][7]10] and their thermo electric power is markedly higher [5][6][7][9][10][11] than those of the parent phase Ca 3 Co 4 O 9 .…”

Section: Introductionmentioning

confidence: 99%

“…A number of studies [5][6][7][8][9][10][11] examined the possibil ity of improving the thermoelectric performance of Ca 3 Co 4 O 9 + δ through partial substitution of 3d transi tion metal ions for cobalt ions in this material. According to Xu et al [5], at x ≤ 0.2 titanium ions sub stitute on the cobalt site in the [Ca 2 CoO 3 ] layers, whereas at x = 0.3 titanium ions reside in both the [Ca 2 CoO 3 ] and [CoO 2 ] layers of the crystal structure of the Ca 3 Co 4 -x Ti x O 9 solid solutions, which leads to a substantial increase in their thermoelectric power.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, structure, and properties of Ca3Co3.85M0.15O9 + δ (M = Ti–Zn, Mo, W, Pb, Bi) layered thermoelectrics

Klyndyuk

Мацукевич

2015

Inorg Mater

View full text Add to dashboard Cite

We have prepared Ca 3 Co 3.85 M 0.15 O 9 + δ (M = Ti-Zn, Mo, W, Pb, Bi) solid solutions, investigated their crystal structure and microstructure, assessed their thermal stability in air, and measured their thermal expansion, electrical conductivity, and thermoelectric power in air at temperatures from 300 to 1100 K. The results demonstrate that the Ca 3 Co 3.85 M 0.15 O 9 + δ cobaltites are p type semiconductors and that their unit cell parameters decrease with an increase in the number of d electrons in the 3d transition metal ion and with an increase in the average oxidation state of the cobalt. Their thermoelectric power increases with increasing temperature, reaching the highest value in the Ca 3 Co 3.85 Pb 0.15 O 9 + δ solid solution: 380 μV/K at a tempera ture of 1100 K. The Ca 3 Co 3.85 Bi 0.15 O 9 + δ solid solution has the largest thermoelectric power factor among the materials studied, 206 μW/(m K 2 ) at a temperature of 1100 K, which is twice the power factor of the unsub stituted calcium cobaltite Ca 3 Co 4 O 9 + δ .

show abstract

The effect of Cr substitution on the structure and properties of misfit-layered Ca3Co4−xCrxO9+δ thermoelectric oxides

Cited by 40 publications

References 40 publications

Local structure determination of substitutional elements in Ca₃Co_4−xM_xO₉(M = Fe, Cr, Ga) using X-ray absorption spectroscopy

Local structure determination of substitutional elements in Ca₃Co_4−xM_xO₉(M = Fe, Cr, Ga) using X-ray absorption spectroscopy

Tailoring Ca3Co4O9 microstructure and performances using a transient liquid phase sintering additive

Synthesis, structure, and properties of Ca3Co3.85M0.15O9 + δ (M = Ti–Zn, Mo, W, Pb, Bi) layered thermoelectrics

Contact Info

Product

Resources

About

The effect of Cr substitution on the structure and properties of misfit-layered Ca3Co4−xCrxO9+δ thermoelectric oxides

Cited by 40 publications

References 40 publications

Local structure determination of substitutional elements in Ca3Co4−xMxO9(M = Fe, Cr, Ga) using X-ray absorption spectroscopy

Local structure determination of substitutional elements in Ca3Co4−xMxO9(M = Fe, Cr, Ga) using X-ray absorption spectroscopy

Tailoring Ca3Co4O9 microstructure and performances using a transient liquid phase sintering additive

Synthesis, structure, and properties of Ca3Co3.85M0.15O9 + δ (M = Ti–Zn, Mo, W, Pb, Bi) layered thermoelectrics

Contact Info

Product

Resources

About

Local structure determination of substitutional elements in Ca₃Co_4−xM_xO₉(M = Fe, Cr, Ga) using X-ray absorption spectroscopy

Local structure determination of substitutional elements in Ca₃Co_4−xM_xO₉(M = Fe, Cr, Ga) using X-ray absorption spectroscopy