Improvement of dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics for X8R type capacitors via Co2+ doping
Work on giant dielectric CaCu3Ti4O12 (CCTO) ceramics has been continuously ongoing to obtain materials with a high dielectric constant (ε') and low dielectric loss tangent (tanδ) with both values stable over a wide temperature range. Various methods have been used to modify the materials, such...
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Elsevier
2023-10-01
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| Series: | Results in Physics |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2211379723008057 |
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| author | Ekaphan Swatsitang Sasitorn Putjuso Supinya Nijpanich Thanin Putjuso |
| author_facet | Ekaphan Swatsitang Sasitorn Putjuso Supinya Nijpanich Thanin Putjuso |
| author_sort | Ekaphan Swatsitang |
| collection | DOAJ |
| description | Work on giant dielectric CaCu3Ti4O12 (CCTO) ceramics has been continuously ongoing to obtain materials with a high dielectric constant (ε') and low dielectric loss tangent (tanδ) with both values stable over a wide temperature range. Various methods have been used to modify the materials, such as doping and co-doping with different transition metals at Ca or Cu sites, molar variation of metals (Cu, Ca and Ti), including altering in the methods and conditions of ceramic preparation. In general, the most common problem found in this type of research is that increasing ε' also increases tanδ. Thus, in this work, a one-step polymer pyrolysis (PP) procedure was used to obtain Co2+-doped CaCu3-xCoxTi4.2O12 (x = 0.00, 0.03, 0.05, and 0.07) powders. Then, all powders were sintered to obtain ceramics using two different sintering conditions, 1050 °C for 10 h and 1080 °C for 5 h. The influence of Co2+ ions and sintering conditions on the microstructure, dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics was investigated. Substitution of Co2+ ions at Cu sites can reduce tanδ values and increase ε' in samples with x = 0.03 and 0.05. However, the tanδ and ε' values were concurrently reduced for x = 0.07. Remarkably, a ceramic with x = 0.07 sintered at 1080 °C for 5 h exhibited very low tanδ(∼0.009) and colossal ε' (∼11551) at 1 kHz and 30 °C, over a broad temperature range (−60 to 150 °C), with stability of Δε' ≤ ±15 %. This ceramic is a suggested candidate material for X8R capacitors. Moreover, increasing the Co2+ doping level could significantly raise the nonlinear coefficient (α) of the ceramics from ∼ 3.48 to 34.30. Additionally, the very high Eb values of ceramics with x = 0.07 sintered at 1050 °C for 10 h and 1080 °C for 5 h were significantly increased by ∼26.34 and 17.45 times, respectively, compared to an undoped ceramic. A widened temperature range where Δε' ≤ ±15 % and tanδ < 0.05 in all ceramics with increasing Co2+ concentration is likely a result of increased grain boundary resistance. |
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| id | doaj.art-82307d4edbcc44b3b3b21a2e94772dcc |
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| issn | 2211-3797 |
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| spelling | doaj.art-82307d4edbcc44b3b3b21a2e94772dcc2023-10-13T11:04:26ZengElsevierResults in Physics2211-37972023-10-0153107012Improvement of dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics for X8R type capacitors via Co2+ dopingEkaphan Swatsitang0Sasitorn Putjuso1Supinya Nijpanich2Thanin Putjuso3Institute of Nanomaterials Research and Innovation for Energy (IN-RIE), NANOTEC-KKU RNN on Nanomaterials Research and Innovation for Energy, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002, ThailandDepartment of General Education (Physics and Mathematics), Faculty of Liberal Arts, Rajamangala University of Technology Rattanakosin, Wang Klai Kangwon Campus, Hua Hin, Prachuap Khiri khan 77110, ThailandSynchrotron Light Research Institute (Public Organization), 111 University Avenue, Muang District, Nakhon Ratchasima 30000, ThailandDepartment of General Education (Physics and Mathematics), Faculty of Liberal Arts, Rajamangala University of Technology Rattanakosin, Wang Klai Kangwon Campus, Hua Hin, Prachuap Khiri khan 77110, Thailand; Corresponding author.Work on giant dielectric CaCu3Ti4O12 (CCTO) ceramics has been continuously ongoing to obtain materials with a high dielectric constant (ε') and low dielectric loss tangent (tanδ) with both values stable over a wide temperature range. Various methods have been used to modify the materials, such as doping and co-doping with different transition metals at Ca or Cu sites, molar variation of metals (Cu, Ca and Ti), including altering in the methods and conditions of ceramic preparation. In general, the most common problem found in this type of research is that increasing ε' also increases tanδ. Thus, in this work, a one-step polymer pyrolysis (PP) procedure was used to obtain Co2+-doped CaCu3-xCoxTi4.2O12 (x = 0.00, 0.03, 0.05, and 0.07) powders. Then, all powders were sintered to obtain ceramics using two different sintering conditions, 1050 °C for 10 h and 1080 °C for 5 h. The influence of Co2+ ions and sintering conditions on the microstructure, dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics was investigated. Substitution of Co2+ ions at Cu sites can reduce tanδ values and increase ε' in samples with x = 0.03 and 0.05. However, the tanδ and ε' values were concurrently reduced for x = 0.07. Remarkably, a ceramic with x = 0.07 sintered at 1080 °C for 5 h exhibited very low tanδ(∼0.009) and colossal ε' (∼11551) at 1 kHz and 30 °C, over a broad temperature range (−60 to 150 °C), with stability of Δε' ≤ ±15 %. This ceramic is a suggested candidate material for X8R capacitors. Moreover, increasing the Co2+ doping level could significantly raise the nonlinear coefficient (α) of the ceramics from ∼ 3.48 to 34.30. Additionally, the very high Eb values of ceramics with x = 0.07 sintered at 1050 °C for 10 h and 1080 °C for 5 h were significantly increased by ∼26.34 and 17.45 times, respectively, compared to an undoped ceramic. A widened temperature range where Δε' ≤ ±15 % and tanδ < 0.05 in all ceramics with increasing Co2+ concentration is likely a result of increased grain boundary resistance.http://www.sciencedirect.com/science/article/pii/S2211379723008057Polymer pyrolysisCaCu3-xCoxTi4.2O12Dielectric propertiesTemperature stabilityX8R capacitor |
| spellingShingle | Ekaphan Swatsitang Sasitorn Putjuso Supinya Nijpanich Thanin Putjuso Improvement of dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics for X8R type capacitors via Co2+ doping Results in Physics Polymer pyrolysis CaCu3-xCoxTi4.2O12 Dielectric properties Temperature stability X8R capacitor |
| title | Improvement of dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics for X8R type capacitors via Co2+ doping |
| title_full | Improvement of dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics for X8R type capacitors via Co2+ doping |
| title_fullStr | Improvement of dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics for X8R type capacitors via Co2+ doping |
| title_full_unstemmed | Improvement of dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics for X8R type capacitors via Co2+ doping |
| title_short | Improvement of dielectric properties and thermal stability of CaCu3Ti4.2O12 ceramics for X8R type capacitors via Co2+ doping |
| title_sort | improvement of dielectric properties and thermal stability of cacu3ti4 2o12 ceramics for x8r type capacitors via co2 doping |
| topic | Polymer pyrolysis CaCu3-xCoxTi4.2O12 Dielectric properties Temperature stability X8R capacitor |
| url | http://www.sciencedirect.com/science/article/pii/S2211379723008057 |
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