Qinglei Zhang

Enhanced dielectric and ferroelectric properties of Pb(Zr0.8Ti0.2)O3∕Pb(Zr0.2Ti0.8)O3 multilayered thin films prepared by rf magnetron sputtering

The Pb(Zr1−xTix)O3 multilayered films consisting of Pb(Zr0.8Ti0.2)O3 and Pb(Zr0.2Ti0.8)O3 layers were deposited on LaNiO3(110)∕Pt∕Ti∕SiO2∕Si substrates by rf magnetron sputtering. All films comprise five periodicities, the layer thicknesses of rhombohedral (dR) and tetragonal (dT) phases in one periodicity are varied. The LaNiO3 buffer layer leads to the (101)∕(110) orientation of the films. The electrical properties of the films were investigated as a function of dR∕dT. The films with dR∕dT=1:2 possess enhanced dielectric and ferroelectric properties. The mechanism of the enhanced electrical properties was discussed, and it was found that the strain is also an important factor to affect electrical properties.

Preparation and properties of highly (100)-oriented Pb(Zr0.2Ti0.8)O3 thin film prepared by rf magnetron sputtering with a PbOx buffer layer

A method for fabrication of highly (100)-oriented Pb(Zr0.2Ti0.8)O3 (PZT) thin films by rf magnetron sputtering with a special buffer of PbOx (RFMS-SBP) was developed. With this method, highly (100)-oriented Pb(Zr0.2Ti0.8)O3 thin films were prepared on the PbOx∕Pt(111)∕Ti∕SiO2∕Si(100) substrates, and the preferential (100) orientation of the Pb(Zr0.2Ti0.8)O3 film is 92%. The (100) orientation of the PbOx buffer layer leads to the (100) orientation of the PZT thin films, and the thickness of the buffer layer plays a significant role on the phase purity and electrical properties of the films. Highly (100)-oriented Pb(Zr0.2Ti0.8)O3 thin films with proper thickness of PbOx buffer layer possess good electrical properties with larger remnant polarization Pr (69.7 μC∕cm2), lower coercive field Ec (92.4 kV/cm), and good pyroelectric coefficient at room temperature (2.6×10−8 C∕cm2 K). The butterfly-shaped e-E characteristic curve gives the evidence of the improved in-plane ferroelectric property in the films.

The Effect of PbO x Buffer Layer on the Properties of Pb(Zr x Ti1−x )O3 Thin Films Prepared by RF Magnetron Sputtering

A method for fabrication of highly (100)-oriented Pb(Zr x Ti1−x )O 3 thin films by RF magnetron sputtering with a special buffer of PbO x (RFMS-SBP) was developed. With this method, highly (100)-orientated Pb(Zr 0.2 Ti 0.8 )O 3 films were prepared on PbO x /Pt(111)/Ti/SiO 2 /Si(100) substrates, and the preferential (100) orientation of the film is 92%. The effect of the thickness of PbO x buffer layer on Pb(Zr 0.2 Ti 0.8 )O 3 films was investigated. The PZT thin films with proper thickness of PbO x buffer layer possesses excellent ferroelectric properties with higher remnant polarization (P r = 69.7 μC/cm 2 ), lower coercive field (E c = 97.5 kV/cm), and the larger pyroelectric coefficient (p = 2.6 × 10 −8 C/cm 2 .K) at room temperature.

Preparation and Properties of PbTiO3/(Pb1−x La x )TiO3/PbTiO3 Multi-Layer Films by RF Magnetron Sputtering

Highly (100)-oriented PbTiO 3 /(Pb 0.90 La 0.10 )Ti 0.975 O 3 /PbTiO 3 multi-layer films were prepared on the PbO x /Pt(111)/Ti/SiO2/Si(100) substrates at the temperature of 600°C by RF magnetron sputtering. The thickness of PbO x buffer layer plays a significant role on the phase purity, and the PbTiO 3 layer plays an important role in improving the properties of the multi-layer films. Highly (100)-orientated PbTiO 3 /(Pb 0.90 La 0.10 )Ti 0.975 O 3 /PbTiO 3 multi-layer film possesses good ferroelectric properties with remnant polarization 2P r = 44.1 μC/cm 2 . The pyroelectric coefficient of the film at room-temperature is 2.425 ×10 −8 C/cm 2 .K. The results indicated that the highly (100)-oriented PbTiO 3 /(Pb 0.90 La 0.10 )Ti 0.975 O 3 /PbTiO 3 film possesses larger remnant polarization together with larger pyroelectric coefficient at room temperature.