Next Article in Journal
Wet-Induced Fabrication of Heterogeneous Hump-on-String Fibers
Next Article in Special Issue
Notched Long-Period Fiber Grating with an Amine-Modified Surface Nanostructure for Carbon Dioxide Gas Sensing
Previous Article in Journal
Dihydrogen Phosphate Stabilized Ruthenium(0) Nanoparticles: Efficient Nanocatalyst for The Hydrolysis of Ammonia-Borane at Room Temperature
Previous Article in Special Issue
Investigation of the High Mobility IGZO Thin Films by Using Co-Sputtering Method
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Materials
Volume 8
Issue 7
10.3390/ma8074239
materials-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Preparation and Properties of (YCa)(TiMn)O3−d Ceramics Interconnect of Solid Oxide Fuel Cells

by
Yi-Cheng Liou
1,2,*,
Wen-Chou Tsai
1,2,
Hao-Hsuan Yen
1 and
Yung-Chia Chang
1
1
Department of Electronic Engineering, Kun Shan University, No.195, Kunda Rd., Yongkang Dist., Tainan City 71070, Taiwan
2
Nano Technology R&D Center, Kun Shan University, No.195, Kunda Rd., Yongkang Dist., Tainan City 71070, Taiwan
*
Author to whom correspondence should be addressed.
Materials 2015, 8(7), 4239-4248; https://doi.org/10.3390/ma8074239
Submission received: 7 June 2015 / Revised: 26 June 2015 / Accepted: 6 July 2015 / Published: 10 July 2015
(This article belongs to the Special Issue Selected Papers from ICASI 2015)
Browse Figures
Versions Notes

Abstract

:
(YCa)(TiMn)O3–δ ceramics prepared using a reaction-sintering process were investigated. Without any calcination involved, the mixture of raw materials was pressed and sintered directly. Y2Ti2O7 instead of YTiO3 formed when a mixture of Y2O3 and TiO2 with Y/Ti ratio 1/1 were sintered in air. Y2Ti2O7, YTiO2.085 and some unknown phases were detected in Y0.6Ca0.4Ti0.6Mn0.4O3–δ. Monophasic Y0.6Ca0.4Ti0.4Mn0.6O3–δ ceramics were obtained after 1400–1500 °C sintering. Dense Y0.6Ca0.4Ti0.4Mn0.6O3–δ with a density 4.69 g/cm3 was observed after 1500 °C/4 h sintering. Log σ for Y0.6Ca0.4Ti0.6Mn0.4O3–δ increased from –3.73 Scm–1 at 350 °C to –2.14 Scm–1 at 700 °C. Log σ for Y0.6Ca0.4Ti0.4Mn0.6O3–δ increased from –2.1 Scm–1 at 350 °C to –1.36 Scm–1 at 700 °C. Increasing Mn content decreased activation energy Ea and increased electrical conductivity. Reaction-sintering process is proved to be a simple and effective method to obtain (YCa)(TiMn)O3–δ ceramics for interconnects in solid oxide fuel cells.

1. Introduction

Solid oxide fuel cells (SOFCs) transform chemical energy from fuels, such as natural gas, humidified hydrogen, into electrical energy with high conversion efficiency and low pollution. An SOFC includes three principal components: the electrolyte, the cathode and the anode. Each part of the SOFC needs to be compatible both physically and chemically with one another to minimize interfacial reactions. A dense electrolyte is needed to prevent gas mixing, whereas the cathode and the anode must be porous to allow gas transport to the reaction sites. SOFCs generate electricity through the oxidation of fuel at anode and the reduction of oxygen at cathode. To provide a high voltage and power output, interconnects are used to connect the cells in series.
Lanthanum chromite (LaCrO3) based perovskite oxides have been widely investigated as the ceramic interconnect for SOFCs due to their fairly high electrical conductivity and excellent thermodynamic stability at higher temperature [1,2]. La0.7Ca0.3Cr0.5Co0.5O3 was reported with very high conductivity 85 Scm–1 at 700 °C. However, its thermal expansion coefficient (TEC) increases from 11.12 × 10–6 to 19 × 10–6 K–1 due to the Co addition. This is much larger than acceptable values 11 × 10–6–12 × 10–6 K–1 for SOFC’s design [1,3,4,5]. Dense LaCrO3 based ceramics are not easy to prepare, besides, stoichiometric pellets are difficult to form because the high vapor pressure of constituent chromium at high temperature. To improve the sinterability of LaCrO3, some methods such as adding sintering aid, using a reducing atmosphere, and substituting lanthanum with other elements were tried by many researchers [6,7,8,9,10,11,12]. Chick et al. found La0.7CaxCrO3 with Ca deficiency, x = 0.28 and 0.29, never attained 60% density, even at 1550 °C sintering. In contrast, the samples with Ca enrichment, x = 0.31 and 0.32, attained densities over 90% at 1400 °C sintering [12]. Mori et al. reported La0.8Sr0.2CrO3 having an average linear TEC of 9.9 × 10–6 K–1 in air and 12.2 × 10–6 K–1 in H2 atmosphere, in the temperature range from 50 to 1000 °C [13]. Yang and co-workers investigated La1–xSrxCrO3 (x = 0–0.3) powder materials synthesized by the glycine-nitrate-process and found the maximum electrical conductivity 14.7 Scm–1 at 1000 °C in La0.8Sr0.2CrO3 sintered at 1550 °C/2 h [14]. Properties for LaCrO3 based oxides have been improved when part of La is substituted by Ca or Sr.
Cr-free oxides were also investigated as interconnect for SOFCs. Taguchi et al. reported perovskite-type (La0.1Ca0.9)(Mn1–xTix)O3 (0 ≤ x ≤ 0.9) are n-type semiconductors at low temperature. At high temperature, the manganates exhibit a metal–insulator transition in the range 0 ≤ x ≤ 0.3 [15]. Vashook et al. investigated perovskite-type compounds La1–xCaxTiO3 (x = 0.2–1.0) and La2(1–x)/3CaxTiO3 (x = 0, 0.1, 0.4 and 0.8). The crystal structures of the La1–xCaxTiO3 compounds at room temperature were as orthorhombic in space group Pbnm (samples with 0.7 ≤ x ≤ 1) and as rhombohedral (x = 0.6). At room temperature three different perovskite-like structures has been found for A-deficient La2(1–x)/3CaxTiO3 compound: orthorhombic Pbnm structure for x = 0.8, orthorhombic Imma structure for x = 0.4, and monoclinic P2/m (or possibly orthorhombic Cm2m) structure for x = 0.1 [16]. Kobayashi et al. reported the crystal structures of Ca0.5R0.5Mn0.5Ti0.5O3 (R = La, Nd, Eu) and Ca0.67R0.33Mn0.33Ti0.67O3 (R = Y, Gd, Dy, Ho, Yb) are orthorhombic Pnma (No. 62) corresponding to GdFeO3 type perovskite structure. The cell parameters b, c and cell volume increase with increasing ionic radius of rare earth element. The decrease in ionic radius of rare earth ions in these compounds makes increase distortion from ideal cubic perovskite [17]. Hosseini et al. fabricated lanthanum–manganese-doped CaTiO3 perovskite oxides La0.4Ca0.6Ti1–xMnxO3–δ (x = 0.0, 0.2, 0.4, 0.6) powders using an EDTA-citrate method and co-sintered as an interconnect material on an extruded porous anode substrate in a flat-tubular solid oxide fuel cell. The highest electrical conductivity occurs when x = 0.6; at 12.20 S cm–1 and 2.70 S cm–1 under oxidizing and reducing conditions [18]. Y3+ has typically been used to replace La3+ in ceramics containing lanthanum to improve their properties. We try to investigate the possibility of using (YCa)(TiMn)O3−δ ceramics as interconnect for SOFCs.
In our previous studies, Pb(Mg1/3Nb2/3)O3 (PMN) and Pb(Fe1/2Nb1/2)O3 (PFN) ceramics had been prepared via a simple and effective reaction-sintering process [19,20]. Dense PMN ceramics (8.09 g/cm3, 99.5% of theoretic density 8.13 g/cm3) with maximum dielectric constant 19,900 at 1 kHz were obtained. Other Pb-based complex perovskite ceramics were also successfully produced by this reaction-sintering process. In our recent investigations, some microwave dielectric ceramics such as BaTi4O9, Ba5Nb4O15, Sr5Nb4O15, CaNb2O6, NiNb2O6, Zn0.5Ti0.5NbO4 and Ni0.5Ti0.5NbO4 were also prepared via this simple and effective reaction-sintering process [21,22,23,24,25,26]. In this study, preparation and properties of (YCa)(TiMn)O3−δ ceramics via a reaction-sintering process were investigated.

2. Results and Discussion

The XRD profiles for the 2 h sintered YTiO3 (YT), Y0.6Ca0.4Ti0.6Mn0.4O3−δ (YCTM4) and Y0.6Ca0.4Ti0.4Mn0.6O3−δ (YCTM6) ceramics are illustrated in Figure 1. The reflections for YT in Figure 1a match well with those of Y2Ti2O7 (ICDD PDF # 00-042-0413) instead those of YTiO3 (ICDD PDF # 00-027-1481). This implies that Y2Ti2O7 formed more easily than YTiO3 as the raw materials with Y/Ti ratio 1/1 were heated in air. Weak peaks (+) around 30° and 50.4° 2θ for YTiO2.085 are seen in Figure 1a. Gill et al. prepared Y2Ti2O7 from Y2O3 and Ti2O3. After 800 °C/12 h calcining, Y2Ti2O7 phase along with weak YTiO2.085 phase was detected for pellets sintered at 1500 °C/12 h. Almost monophasic YTiO2.085 phase was detected for pellets sintered at 1550 °C/12 h [27]. The reflections for YCTM4 in Figure 1b show that a phase with similar crystal structure of YTiO3 formed as the major phase and Y2Ti2O7 phase still formed in YCTM4. Weak peaks for YTiO2.085 and some unknown phases are seen in Figure 1b. The reflections for major phase are also similar to those for Y0.33Ca0.67Ti0.67Mn0.33O3 reported by Kobayashi et al. [17]. The crystal structure for YCTM4 is different from YT as Ca and Mn were added. The reflections for YCTM6 in Figure 1c show that only a phase with similar crystal structure of YTiO3 and Y0.33Ca0.67Ti0.67Mn0.33O3 reported by Kobayashi et al. [17] formed. Y2Ti2O7 phase is not detected. More Mn addition inhibited the formation of Y2Ti2O7, YTiO2.085, and unknown phases. The reaction-sintering process is proved to be a simple and effective process to obtain YT, YCTM4 and YCTM6 ceramics. The calcination step of the conventional mixed oxide route was performed during the heating up period.
Relative density of YT, YCTM4 and YCTM6 ceramics sintered at various temperatures and soak time is shown in Figure 2. A low density, 69.1% of the theoretical density 4.98 g/cm3 for Y2Ti2O7, was found for 1400 °C/2 h sintering YT pellets. Density of YT increased with sintering temperature and soak time. Dense YT with 91.4% of the theoretical density for Y2Ti2O7 was observed after being sintered at 1500 °C/6 h. Gill et al. prepared Y2Ti2O7 and obtained a low density 73% of the theoretical density after 800 °C/12 h calcining and 1500 °C/12 h sintering [27]. YCTM4 pellets show lower densities. YCTM4 with 77.9% of the theoretical density ~4.97 g/cm3 for Y0.6Ca0.4Ti0.6Mn0.4O3−δ was observed even after sintering at 1500 °C/6 h. Lower densities may be caused by the unknown phases, pores, and YTiO2.085 with a low density 4.28 g/cm3. A higher sintering temperature or a prolonged sintering period is suggested for obtaining dense YCTM4. YCTM6 pellets show higher densities. Dense YCTM6 with 93.6% of the theoretical density ~5.01 g/cm3 for Y0.6Ca0.4Ti0.4Mn0.6O3−δ was observed after being sintered at 1500 °C/4 h. The reaction-sintering process is proved to be effective at obtaining YT and YCTM6 ceramics with a relative density higher than 90%.
Materials 08 04239 g001 1024
Figure 1. XRD patterns of the 2 h sintered (a) YTiO3 (YT); (b) Y0.6Ca0.4Ti0.6Mn0.4O3−δ(YCTM4); (c) Y0.6Ca0.4Ti0.4Mn0.6O3−δ (YCTM6) ceramics. +: YTiO2.085; ?: unknown phases.
Figure 1. XRD patterns of the 2 h sintered (a) YTiO3 (YT); (b) Y0.6Ca0.4Ti0.6Mn0.4O3−δ(YCTM4); (c) Y0.6Ca0.4Ti0.4Mn0.6O3−δ (YCTM6) ceramics. +: YTiO2.085; ?: unknown phases.
Materials 08 04239 g001
Materials 08 04239 g002 1024
Figure 2. Relative density of YT, YCTM4, and YCTM6 ceramics sintered at various temperatures and soak time.
Figure 2. Relative density of YT, YCTM4, and YCTM6 ceramics sintered at various temperatures and soak time.
Materials 08 04239 g002
SEM photographs of as-fired YT ceramics sintered at various temperatures and soak time are presented in Figure 3. Porous pellets with grains smaller than 3 μm are seen for 1400 °C/2 h sintering YT pellets. Grain size increased with sintering temperature and soak time. Grains > 10 μm are seen for 1500 °C/6 h sintering YT pellets. Ding et al. prepared Y2Ti2O7 with 1 mol% La2O3 and found grains smaller than 4 μm after 1450 °C/2–4 h sintering [28]. SEM photographs of the YCTM4 ceramics sintered at various temperatures and soak time are presented in Figure 4. Porous pellets with grains smaller than 8 μm are seen for 1400 °C/2 h sintering YCTM4 pellets. Grain size increased with sintering temperature and soak time. Pores disappeared and grains >10 μm are seen for 1500 °C/6 h sintering YCTM4 pellets. Grain growth increased as Ca and Mn were added into YT. Grains <4 μm are seen for La0.4Ca0.6Ti0.6Mn0.4O3–δ via an EDTA-citrate method after 950 °C/5 h calcining and 1400 °C/10 h sintering [18]. Therefore, the reaction-sintering process is proved to be effective for grain growth in YT and YCTM4 ceramics. The calcinations stage and the following pulverization for the conventional solid–state reaction route could be bypassed. SEM photographs of the YCTM6 ceramics sintered at various temperatures and soak time are presented in Figure 5. Porous pellets with grains smaller than 6 μm are seen for 1400 °C/2 h sintering YCTM6 pellets. Grain size increased with sintering temperature and soak time. Pores disappeared and grains > 20 μm are seen for 1500 °C/6 h sintering YCTM6 pellets. More Mn addition increased the grain growth in YCTM6 pellets than in YCTM4 pellets. Grains <4 μm are seen for La0.4Ca0.6Ti0.4Mn0.6O3–δ via an EDTA-citrate method after 950 °C/5 h calcining and 1400 °C/10 h sintering [18]. It is noted some cracks are seen in YCTM6 pellets. These cracks propagated not only along the grain boundaries but also through the grains. Besides, the amount and the size of cracks increased with sintering temperature and soak time. Sintering at temperatures below 1450 °C for a prolonged period or adding sintering aids are suggested for obtaining dense YCTM6 pellets without cracks.
Materials 08 04239 g003 1024
Figure 3. SEM photographs of the YT ceramics sintered at various temperatures and soak time.
Figure 3. SEM photographs of the YT ceramics sintered at various temperatures and soak time.
Materials 08 04239 g003
Materials 08 04239 g004 1024
Figure 4. SEM photographs of the YCTM4 ceramics sintered at various temperatures and soak time.
Figure 4. SEM photographs of the YCTM4 ceramics sintered at various temperatures and soak time.
Materials 08 04239 g004
Materials 08 04239 g005 1024
Figure 5. SEM photographs of the YCTM6 ceramics sintered at various temperatures and soak time.
Figure 5. SEM photographs of the YCTM6 ceramics sintered at various temperatures and soak time.
Materials 08 04239 g005
DC total conductivity of 1500 °C/6 h sintering YT, YCTM4, and YCTM6 ceramics are shown in Figure 6. Log σ is found from –8.19 Scm–1 at 350 °C to –4.94 Scm–1 at 700 °C for YT. Gill et al. prepared Y2Ti2O7 and obtained log σ about –7.8 Scm–1 at 700 °C and –6.636 Scm–1 at 900 °C after 800 °C/12 h calcining and 1500 °C/12 h sintering [27]. The reaction-sintering process is proved to be effective at obtaining YT ceramics with a higher conductivity even the calcination was bypassed. Log σ is found from –3.73 Scm–1 at 350 °C to –2.14 Scm–1 at 700 °C for YCTM4. Conductivity increased as Ca and Mn were added into YT. σ about 1.5 Scm–1 at 700 °C for La0.4Ca0.6Ti0.6Mn0.4O3–δ via an EDTA-citrate method after 950 °C/5 h calcining and 1400 °C/10 h sintering was obtained [18]. Log σ is found from –2.1 Scm–1 at 350 °C to –1.36 Scm–1 at 700 °C for YCTM6. σ about 7 Scm–1 at 700 °C for La0.4Ca0.6Ti0.4Mn0.6O3–δ via an EDTA-citrate method after 950 °C/5 h calcining and 1400 °C/10 h sintering was obtained [18]. Conductivity further increased as more Mn was added into YCTM4. A similar tendency was also observed in the study of La0.4Ca0.6Ti1–xMnxO3–δ by Hosseini et al. [18]. Conductivity increased as Mn content increased in La0.4Ca0.6Ti1–xMnxO3–δ. According to the Arrhenius relationship [29], the experimental activation energy Ea can be determined from the slope of the line when natural logarithm of conductivity (ln σ) is plotted against 1/T as shown in Figure 6. Ea for YT, YCTM4, and YCTM6 were derived as 1.18, 0.64, and 0.33 eV, respectively. Ea of 1.87 eV for La0.4Ca0.6TiO3–δ and Ea of 0.47 eV for La0.4Ca0.6Ti0.8Mn0.2O3–δ was obtained via an EDTA-citrate method after 950 °C/5 h calcining and 1400 °C/10 h sintering [18]. Hosseini et al. thought increasing Mn content decreased Ea and increased electrical conductivity in air. Increasing Mn content causes the number of oxygen vacancies to increase and this in turn causes an increase in electron hole concentration [18]. A similar tendency was also observed in this study.
Materials 08 04239 g006 1024
Figure 6. log σ and ln (σT) of 1500 °C/6 h sintering YT, YCTM4, and YCTM6 ceramics. (a) log σ; (b) ln (σT).
Figure 6. log σ and ln (σT) of 1500 °C/6 h sintering YT, YCTM4, and YCTM6 ceramics. (a) log σ; (b) ln (σT).
Materials 08 04239 g006

3. Experimental Section

YTiO3 (YT), Y0.6Ca0.4Ti0.6Mn0.4O3−δ (YCTM4) and Y0.6Ca0.4Ti0.4Mn0.6O3−δ (YCTM6) samples in this study were prepared from reagent-grade powders: Y2O3 (99.9%, STREM CHEMICALS, Newburyport, MA, USA), CaCO3 (99%, SHOWA, Tokyo, Japan), TiO2 (99.9%, SHOWA, Tokyo, Japan), and MnO2 (99.9%, J.T. Baker, Phillipsburg, NJ, USA). Appropriate amounts of raw materials for each batch were weighed and put into a PE (Polyethylene) bottle. Zirconia balls with 5 and 10 mm diameters were used for milling the raw mother powders with de-ionized water for 12 h at a speed of 500 rpm. The dried and pulverized powders were pressed into pellets with 12 mm in diameter and 1–2 mm thick. The pellets were sintered at 1400–1500 °C at a rate 10 °C/min in a covered alumina crucible in air.
The reflections of various phases for the sintered pellets were analyzed by XRD. Microstructures were analyzed by scanning electron microscopy (SEM). The density of the sintered pellets was measured using the Archimedes method. Ag electrodes were formed on both sides of the sintered pellets. Agilent 34970A Data Acquisition was used for electrical resistivity measurements at 350–700 °C.

4. Conclusions

(YCa)(TiMn)O3−δ ceramics could be effectively obtained via a simple reaction-sintering process with the calcining stage bypassed. Y2Ti2O7 instead of YTiO3 formed when a mixture of Y2O3 and TiO2 with Y/Ti ratio 1/1 were heated in air. Y2Ti2O7, YTiO2.085 and some unknown phases were detected in Y0.6Ca0.4Ti0.6Mn0.4O3-δ. Monophasic Y0.6Ca0.4Ti0.4Mn0.6O3−δ ceramics were obtained after 1400–1500 °C sintering. Y0.6Ca0.4Ti0.6Mn0.4O3−δ with a density 3.87 g/cm3 was observed even at 1500 °C/6 h sintering. Dense Y0.6Ca0.4Ti0.4Mn0.6O3−δ with a density 4.69 g/cm3 was observed after 1500 °C/4 h sintering. Some cracks are seen in Y0.6Ca0.4Ti0.4Mn0.6O3−δ pellets. Log σ is found from –3.73 Scm–1 at 350 °C to –2.14 Scm–1 at 700 °C for Y0.6Ca0.4Ti0.6Mn0.4O3−δ. Log σ is found from –2.1 Scm–1 at 350 °C to –1.36 Scm–1 at 700 °C for Y0.6Ca0.4Ti0.4Mn0.6O3−δ. Increasing Mn content decreased activation energy Ea and increased electrical conductivity. Reaction-sintering process is proved to be a simple and effective method for obtaining (YCa)(TiMn)O3−δ ceramics for interconnects in solid oxide fuel cells.

Author Contributions

Yi-Cheng Liou formulated research ideas and wrote initial manuscript. Analysis of data was performed by Yi-Cheng Liou and Wen-Chou Tsai. Hao-Hsuan Yen and Yung-Chia Chang performed the experiments. All authors read and approved the manuscript.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Fergus, J.W. Lanthanum chromite-based materials for solid oxide fuel cell interconnects. Sol. State Ion. 2004, 171, 1–15. [Google Scholar] [CrossRef]
  2. Sakai, N.; Kawada, T.; Yokokawa, H.; Dokiya, M. Sinterability and electrical conductivity of calcium-doped lanthanum chromites. J. Mater. Sci. 1990, 25, 4531–4534. [Google Scholar] [CrossRef]
  3. Tao, S.W.; Irvine, J.T.S. A redox-stable efficient anode for solid-oxide fuel cells. Nat. Mater. 2003, 2, 320–323. [Google Scholar] [CrossRef] [PubMed]
  4. Zhu, W.Z.; Deevi, S.C. Development of interconnect materials for solid oxide fuel cells. Mater. Sci. Eng. A 2003, 348, 227–243. [Google Scholar] [CrossRef]
  5. Sakai, N.; Yokokawa, H.; Horita, T.; Yamaji, K. Lanthanum chromite-based interconnects as key materials for SOFC stack development. Int. J. Appl. Ceram. Tech. 2004, 1, 23–30. [Google Scholar] [CrossRef]
  6. Groupp, L.; Anderson, H.U. Densification of La1−xSixCrO3. J. Am. Ceram. Soc. 1976, 59, 449–450. [Google Scholar] [CrossRef]
  7. Sakai, N.; Kawada, T.; Yokokawa, H.; Dokiya, M.; Kojima, I. Liquid-phase-assisted sintering of calcium-doped lanthanum chromites. J. Am. Ceram. Soc. 1993, 76, 609–616. [Google Scholar] [CrossRef]
  8. Hayashi, S.; Fukaya, K.; Saito, H. Sintering of lanthanum chromite doped with zinc or copper. J. Mater. Sci. Lett. 1988, 7, 457–458. [Google Scholar] [CrossRef]
  9. Bansal, K.P.; Kumari, S.; Das, B.K.; Jain, G.C. Electrical conduction in titania-doped lanthanum chromite ceramics. J. Mater. Sci. 1981, 16, 1994–1998. [Google Scholar] [CrossRef]
  10. Sammes, N.M.; Ratnaraj, R.; Fee, M.G. The effect of sintering on the mechanical properties of SOFC ceramic interconnect materials. J. Mater. Sci. 1994, 29, 4319–4324. [Google Scholar] [CrossRef]
  11. Wang, J.; Ponton, C.B.; Marquis, P.M. Sintering and microstructural development of La0.80Ca0.22CrO3. J. Mater. Sci. Lett. 1996, 15, 658–661. [Google Scholar] [CrossRef]
  12. Chick, L.A.; Liu, J.; Stevenson, J.W.; Armtrong, T.R.; McCready, D.E.; Maupin, G.D.; Coffey, G.W.; Coyle, C.A. Phase transitions and transient liquid-phase sintering in calcium-substituted lanthanum chromite. J. Am. Ceram. Soc. 1997, 80, 2109–2120. [Google Scholar] [CrossRef]
  13. Mori, M.; Yamamoto, T.; Itoh, H.; Watanabe, T. Compatibility of alkaline earth metal (Mg, Ca, Sr)-doped lanthanum chromites as separators in planar-type high-temperature solid oxide fuel cells. J. Mater. Sci. 1997, 32, 2423–2431. [Google Scholar] [CrossRef]
  14. Yang, Y.J.; Wen, T.L.; Tu, H.; Wang, D.Q.; Yang, J. Characteristics of lanthanum strontium chromite prepared by glycine nitrate process. Sol. State Ion. 2000, 135, 475–479. [Google Scholar] [CrossRef]
  15. Taguchi, H.; Sonoda, M.; Nagao, M.; Kido, H. Role of tetravalent ion in metal–insulator transition in (La0.1Ca0.9)(Mn1−xTix)O3. J. Sol. State Chem. 1996, 126, 235–241. [Google Scholar] [CrossRef]
  16. Vashook, V.; Vasylechko, L.; Knapp, M.; Ullmann, H.; Guth, U. Lanthanum doped calcium titanates: Synthesis, crystal structure, thermal expansion and transport properties. J. Alloy. Compd. 2003, 354, 13–23. [Google Scholar] [CrossRef]
  17. Kobayashi, M.; Katsuraya, R.; Kurita, S.; Yamaguchi, M.; Satoh, H.; Kamegashira, N. Synthesis and crystal structure of (Ca,R)(Mn,Ti)O3 (R,rare earth). J. Alloy. Compd. 2006, 408–412, 1173–1176. [Google Scholar] [CrossRef]
  18. Hosseini, N.R.; Sammes, N.M.; Chung, J.S. Manganese-doped lanthanum calcium titanate as an interconnect for flat-tubular solid oxide fuel cells. J. Power Sour. 2014, 245, 599–608. [Google Scholar] [CrossRef]
  19. Liou, Y.C.; Tseng, K.H. Stoichiometric Pb(Mg1/3Nb2/3)O3 perovskite ceramics produced by reaction-sintering process. Mater. Res. Bull. 2003, 38, 1351–1357. [Google Scholar] [CrossRef]
  20. Liou, Y.C.; Shih, C.Y.; Yu, C.H. Stoichiometric Pb(Fe1/2Nb1/2)O3 perovskite ceramics produced by reaction-sintering process. Mater. Lett. 2003, 57, 1977–1981. [Google Scholar] [CrossRef]
  21. Liou, Y.C.; Wu, C.T.; Tseng, K.H.; Chung, T.C. Synthesis of BaTi4O9 ceramics by reaction-sintering process. Mater. Res. Bull. 2005, 40, 1483–1489. [Google Scholar] [CrossRef]
  22. Liou, Y.C.; Shiue, W.H.; Shih, C.Y. Microwave ceramics Ba5Nb4O15 and Sr5Nb4O15 prepared by a reaction-sintering process. Mater. Sci. Eng. B 2006, 131, 142–146. [Google Scholar] [CrossRef]
  23. Liou, Y.C.; Weng, M.H.; Shiue, C.Y. CaNb2O6 ceramics prepared by a reaction-sintering process. Mater. Sci. Eng. B 2006, 131, 14–19. [Google Scholar] [CrossRef]
  24. Liou, Y.C.; Shiue, C.Y.; Weng, M.H. Synthesis and properties of TiO2 added NiNb2O6 microwave dielectric ceramics using a simple process. J. Eur. Ceram. Soc. 2009, 29, 1165–1171. [Google Scholar] [CrossRef]
  25. Chen, Y.T.; Liou, Y.C.; Fung, K.Z. (1−x)ZnNb2O6–xTiO2 microwave dielectric ceramics by reaction–sintering process. In Proceedings of the 2007 MRS-T annual meeting, Hsinchu, Taiwan, 16–17 November 2007. (In Chinese)
  26. Chen, Y.T.; Liou, Y.C.; Fung, K.Z. Ni0.5Ti0.5NbO4 microwave ceramics by a reaction-sintering process. In Proceedings of the 2007 MRS-T annual meeting, Hsinchu, Taiwan, 16–17 November 2007. (In Chinese)
  27. Gill, J.K.; Pandey, O.P.; Singh, K. Role of sintering temperature on thermal, electrical and structural properties of Y2Ti2O7 pyrochlores. Int. J. Hydrog. Energy 2011, 36, 14943–14947. [Google Scholar] [CrossRef]
  28. Ding, J.; Xiao, Y.; Han, P.; Zhang, Q. Effects of rare earth oxides on dielectric properties of Y2Ti2O7 series ceramics. J. Rare Earths 2010, 28, 765–768. [Google Scholar] [CrossRef]
  29. Moulson, A.J.; Herbert, J.M. Electroceramics: Materials, Properties, Applications, 2nd ed.; John Wiley & Sons Ltd: Chichester, UK, 2003; p. 32. [Google Scholar]

Share and Cite

MDPI and ACS Style

Liou, Y.-C.; Tsai, W.-C.; Yen, H.-H.; Chang, Y.-C. Preparation and Properties of (YCa)(TiMn)O3−d Ceramics Interconnect of Solid Oxide Fuel Cells. Materials 2015, 8, 4239-4248. https://doi.org/10.3390/ma8074239

AMA Style

Liou Y-C, Tsai W-C, Yen H-H, Chang Y-C. Preparation and Properties of (YCa)(TiMn)O3−d Ceramics Interconnect of Solid Oxide Fuel Cells. Materials. 2015; 8(7):4239-4248. https://doi.org/10.3390/ma8074239

Chicago/Turabian Style

Liou, Yi-Cheng, Wen-Chou Tsai, Hao-Hsuan Yen, and Yung-Chia Chang. 2015. "Preparation and Properties of (YCa)(TiMn)O3−d Ceramics Interconnect of Solid Oxide Fuel Cells" Materials 8, no. 7: 4239-4248. https://doi.org/10.3390/ma8074239

Article Metrics

Back to TopTop