9:45 AM - 10:00 AM
▼ [20a-231A-4] Fabrication of 85(Bi0.5Na0.5)TiO3-15BaTiO3 green body with (001)-textured hexagonal BaTiO3 particles using high magnetic field electrophoretic deposition (HM-EPD)
Keywords:Electrophoretic deposition, BNT-BT, lead-free piezoelectric
85(Bi0.5Na0.5)TiO3-15BaTiO3 (85BNT-15BT) ceramic is representative lead-free piezoelectric ceramic due to its high Curie temperature (~250 oC) and suitability for mass production. To enhance piezoelectric properties, engineered domain structure have been studied which is achieved when crystal is orientated along non-polar direction. 85BNT-15BT ceramic have tetragonal symmetry and non-polar direction is [110] or [111] direction. However, there are very few reports for fabrication of [110] or [111] textured 85BNT-15BT ceramic.
In previous work, our group reported that [111]-textured BaTiO3 (BT) ceramic was fabricated using high magnetic field electrophoretic deposition (HM-EPD). Therefore, we expected that [111]-textured 85BNT-15BT ceramic could be fabricated with HM-EPD method using textured BT particles as orientation seed. Under the magnetic field, diamagnetic particles are orientated along high magnetic susceptibility (χ) direction and the alignment driving force can be expressed as following:
ΔE=ΔχVB2/2µ0 - Eq. 1
where Δχ is magnetic anisotropy, V is particle volume, B is magnetic field and µ0 is magnetic permeability in vacuum. It was reported that [001]-textured hexagonal BT green body was fabricated with HM-EPD method under 12 T of magnetic field. In this case, [111]-textured tetragonal BT ceramic was fabricated during sintering procedure.
In this work, to obtain highly oriented green body, 85BNT-15BT green bodies were fabricated with different particle size of hexagonal BT because particle volume (V) is important factor according to equation 1. From the results, we obtained green body with randomly orientated BNT particles and [001]-textured BT particles with 83% of Lotgering factor. Detailed experimental results will be provided during presentation
In previous work, our group reported that [111]-textured BaTiO3 (BT) ceramic was fabricated using high magnetic field electrophoretic deposition (HM-EPD). Therefore, we expected that [111]-textured 85BNT-15BT ceramic could be fabricated with HM-EPD method using textured BT particles as orientation seed. Under the magnetic field, diamagnetic particles are orientated along high magnetic susceptibility (χ) direction and the alignment driving force can be expressed as following:
ΔE=ΔχVB2/2µ0 - Eq. 1
where Δχ is magnetic anisotropy, V is particle volume, B is magnetic field and µ0 is magnetic permeability in vacuum. It was reported that [001]-textured hexagonal BT green body was fabricated with HM-EPD method under 12 T of magnetic field. In this case, [111]-textured tetragonal BT ceramic was fabricated during sintering procedure.
In this work, to obtain highly oriented green body, 85BNT-15BT green bodies were fabricated with different particle size of hexagonal BT because particle volume (V) is important factor according to equation 1. From the results, we obtained green body with randomly orientated BNT particles and [001]-textured BT particles with 83% of Lotgering factor. Detailed experimental results will be provided during presentation