Rapid Laser Reactive Sintering Synthesis of Colossal Dielectric CCTO Ceramics
| Autor: | Ming Yan, Huang Yanwei, Jiayang He, Guang Feng, Si Shen, Heping Zeng |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Permittivity
Materials science ceramic Sintering 02 engineering and technology Dielectric 01 natural sciences lcsh:Technology lcsh:Chemistry chemistry.chemical_compound CCTO 0103 physical sciences Calcium copper titanate General Materials Science Laser power scaling Composite material Instrumentation lcsh:QH301-705.5 010302 applied physics Fluid Flow and Transfer Processes lcsh:T Process Chemistry and Technology General Engineering 021001 nanoscience & nanotechnology permittivity lcsh:QC1-999 Computer Science Applications Dielectric spectroscopy laser chemistry lcsh:Biology (General) lcsh:QD1-999 lcsh:TA1-2040 impedance Grain boundary Dielectric loss 0210 nano-technology lcsh:Engineering (General). Civil engineering (General) lcsh:Physics |
| Zdroj: | Applied Sciences Volume 10 Issue 10 Applied Sciences, Vol 10, Iss 3510, p 3510 (2020) |
| ISSN: | 2076-3417 |
| DOI: | 10.3390/app10103510 |
| Popis: | Calcium copper titanate (CCTO) ceramics were successfully synthesized using a rapid laser reactive sintering method without conventional long heat treatment times. The microstructure, dielectric properties, and impedance spectroscopy results for CCTO sintered at laser power rates of 25&ndash 85 W were investigated in detail. The X-ray diffractometry results showed that prepared CCTO is polycrystalline in a cubic structure with high purity. Scanning electron microscopy showed that CCTO sintered at 85 W has a dense microstructure with an average grain size of 30 nm. The dielectric permittivity of CCTO ceramics increased with increasing laser power over the entire frequency range and achieved a value of almost 105 in the low-frequency region. The dielectric permittivity maintained almost constant values from 102 Hz to 107 Hz, with lower dielectric loss (~0.1) from 103 Hz to 106 Hz, demonstrating good frequency stability. The impedance spectroscopy study showed that grain and grain boundary resistance decreased with rising laser power based on two parallel Resistor-Capacitance (RC) equivalent circuits in series. The activation energies for the grain boundaries were calculated from the impedance using the slope of ln versus 1/T and were found to be in the range of 0.53&ndash 0.63 eV. CCTO synthesized by rapid laser reactive sintering is competitive for practical applications. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|