A5090697670- Ferroelectric and Piezoelectric Materials
- Acoustic Wave Resonator Technologies
- Microwave Dielectric Ceramics Synthesis
- Advanced Sensor and Energy Harvesting Materials
- Multiferroics and related materials
- Innovative Energy Harvesting Technologies
- Dielectric properties of ceramics
Korea University
2008-2024
An amount of 3.0 mol% NaNbO3 seeds was used to align the grains 0.96(Na0.5K0.5)(Nb0.93Sb0.07)O3-(0.04−x)SrZrO3-x(Bi0.5Ag0.5)ZrO3 [NKNS-(0.04−x)SZ-xBAZ] thick films (0.0 ≤ x 0.04) along [001] direction. All textured had large Lotgering factors (>95%). The NKNS-0.02SZ-0.02BAZ film has a rhombohedral-orthorhombic-tetragonal (R-O-T) structure with proportion R-O (>80%) and nanodomains (0.7 nm in width 6 length). This exhibited d33 value (760 ± 20 pC/N), kp (0.58) strain (0.16% at 4.0...
0.96(K0·5Na0.5-zLiz) (Nb0·92Sb0.08)O3-0.04(Ca0·5Sr0.5)ZrO3 [(KN0.5-zLz)NS-CSZ] piezoceramics (0 ≤ z 0.04) were aligned in the [001] orientation using 3 % (in mole) NaNbO3 templates with a large Lotgering factor (>97 %). Their crystal structures transformed from orthorhombic-pseudocubic (OP) structure to orthorhombic-tetragonal-pseudocubic (O-T-P) an increasing z. The P was interpreted as rhombohedral R3m structure. piezoelectricity of compositions increased after [001]-texturing, and...
The output power of piezoelectric energy harvester (PEH) at the resonance frequency is dependent on electromechanical coupling factor ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1"> <msub> <mrow> <mi>k</mi> </mrow> <mi>p</mi> </msub> </math> ) piezoceramic, which proportional to id="M2"> <mi>d</mi> <mn>33</mn> <mo>/</mo> <msup> <mfenced open="(" close=")"> <mi>ε</mi> <mi>T</mi> </msup> </mfenced> <mn>1</mn> <mn>2</mn> , where id="M3"> and id="M4"> are change dielectric constants,...
The [001]-textured 0.96NK(N 0.99 S 0.01 )–0.01CZ–0.03BAZ piezoceramic has large k p and d 33 × g values; therefore, the piezoelectric energy harvester fabricated using this exhibits a power density.
CuO was used to enhance the sinterability of 0.95(Na 0.5 K )NbO 3 –0.05SrTiO (0.95NKN–0.05ST) ceramics. The poor 0.95NKN–0.05ST ceramics improved by addition 1.5 mol% CuO, so that they were well sintered even at 960°C with grain growth. densification and growth attributed liquid‐phase sintering, probably due presence a liquid phase containing SrO CuO. size decreased when sintering temperature exceeded 960°C, large amount phase. microstructure considerably affected small variations...