[Show abstract][Hide abstract] ABSTRACT: In this work, we report on two kinds of PbZrO3 (PZO) antiferroelectric (AFE) thin films with a thickness of about 700nm, which were fabricated by using zirconium isopropoxide and zirconium nitrate as starting materials, respectively. The effects of the raw materials on microstructure and electrical properties of the PZO AFE films were studied in detail. X-ray diffraction and scanning electron microcopy results showed that the PZO films obtained from zirconium isopropoxide were highly (111)-oriented and had a more uniform surface microstructure. As a result, the PZO films from zirconium isopropoxide accordingly displayed better electrical properties, such as lager dielectric constant, increased saturated polarization, and smaller leakage current.
Journal of Alloys and Compounds 09/2011; 509(35):8779-8782. DOI:10.1016/j.jallcom.2011.06.067 · 3.00 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A 400-nm-thick (Pb0.97La0.02)(Zr0.97Ti0.03)O3 (PLZT 2/97/3) antiferroelectric (AFE) thin films with different lead excess content (0%, 10%, and 20%) were successfully deposited on Pt(111)/TiO2/SiO2/Si substrates via a sol–gel process. The effects of lead excess content on the microstructure, dielectric properties, and energy storage performance of PLZT 2/97/3 AFE thin films were investigated in details. X-ray diffraction results displayed that AFE thin films were changed from the (111)-preferred orientation to the (100) and (111)-mixed orientation with increasing lead excess content. Dielectric measurements showed that AFE thin films with higher lead excess content exhibited enhanced dielectric constant and larger phase transformation fields. Thus, the energy storage density of AFE thin films was also remarkably improved from 3.3 to 11.7 J/cm3 at 1200 kV/cm.
Journal of the American Ceramic Society 05/2011; 94(6):1647 - 1650. DOI:10.1111/j.1551-2916.2011.04460.x · 2.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In the present investigation (Pb0.5Ba0.5)ZrO3 (PBZ) thin films doped by K (KPBZ) from 0 to 5mol% were successfully deposited on Pt-buffered silicon substrates by a sol–gel method. The K content dependence of microstructure and electrical properties of KPBZ thin films were studied in detail. It was found that, although all the films displayed a pure perovskite structure without obvious difference, the surface roughness of KPBZ films was decreased with increasing K content. Dielectric measurements showed that the figure of merit (FOM) values of KPBZ thin films were greatly increased by K-doping, and at the same time that the temperature-dependent stability was also improved. Thus, K doping is a promising way to optimize the overall electrical properties of PBZ thin films for potential application in tunable devices.
Materials Research Bulletin 03/2011; 46(3):420-423. DOI:10.1016/j.materresbull.2010.12.005 · 2.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this paper, we report on the structure and electrical properties of lead zirconate (PbZrO3) thin films doped with barium (Ba2+) and strontium (Sr2+) deposited on platinum-buffered silicon substrates by a sol–gel method. Effects of Ba2+ and Sr2+ dopants on microstructure and electrical properties of the PbZrO3 antiferroelectric thin films were investigated in details. X-ray diffraction patterns and scanning electron microscope micrographs illustrated that orientation and surface microstructure of these antiferroelectric films were dopant-dependent. The dielectric measurements showed that Sr2+ doping stabilized the antiferroelectric phase, while Ba2+ doping destabilized the antiferroelectric phase. It was also found that fatigue property of the antiferroelectric PbZrO3 thin films was improved remarkably by the dopants.
Journal of Alloys and Compounds 01/2011; 509(2):271-275. DOI:10.1016/j.jallcom.2010.07.200 · 3.00 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In the present work, the effects of oxide buffer layers, such as ZrO2, CeO2 and TiO2, on the microstructure and electrical properties of (Pb0.97La0.02)(Zr0.87Sn0.10Ti0.03)O3 (PLZST 2/87/10/3) antiferroelectric (AFE) thin films were investigated systematically. X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) pictures illustrated that the crystalline orientation and surface microstructure of PLZST 2/87/10/3 AFE thin films had a close relation with these oxide buffer layers. As a result, the final electrical properties of AFE films were tuned by these buffer layers. Electrical measurements result showed that the dielectric properties, polarization characteristic and current–field curves of AFE thin films could be tailored by selecting a proper oxide buffer layer.
[Show abstract][Hide abstract] ABSTRACT: Highly (100) and (111)-oriented Pb <sub>0.97</sub> La <sub>0.02</sub>( Zr <sub>0.85</sub> Sn <sub>0.13</sub> Ti <sub>0.02</sub>) O <sub>3</sub> antiferroelectric (AFE) thin films were fabricated through a sol-gel processing. The effects of orientation on phase transformation behaviors and strains of the AFE thin films were studied systemically. As compared to (100)-preferred AFE thin films, the (111)-oriented films showed a smaller forward phase switching field of 250 kV/cm and higher stains of 0.79%. It is therefore concluded that AFE thin films with (111)-preferred orientation are more suitable to be used as microactuators.
[Show abstract][Hide abstract] ABSTRACT: Both up and down compositionally graded (Pb1−xBax)ZrO3 (PBZ) thin films with increasing x from 0.4 to 0.6 were deposited on Pt(1 1 1)-buffer layered silicon substrates through a sol–gel method. The microstructure and dielectric properties of graded PBZ thin films were investigated systemically. X-ray diffraction patterns confirmed that both PBZ films had crystallized into a pure perovskite phase after annealed 700 °C. Electrical measurement results showed that although up graded films had a slightly larger tunability, dielectric loss of down graded films was much lower than that of up graded films. Therefore, the figure of merit of down graded PBZ films was greatly enhanced, as compared with up graded films. Moreover, down graded PBZ thin films also displayed excellent temperature stability with a smaller temperature coefficient of capacitance (TCC) of −0.59 × 10−3 °C−1 from 20 °C to 80 °C.
Journal of Alloys and Compounds 07/2010; 501(2):358-361. DOI:10.1016/j.jallcom.2010.04.104 · 3.00 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: (Pb0.5Ba0.5)ZrO3 (PBZ) and 1mol% Mn-doped (Pb0.5Ba0.5)ZrO3 (Mn-PBZ) sol were successfully fabricated, and corresponding thin films were deposited on Pt(111)/TiO2/SiO2/Si(100) substrates by spin-coating method. Effects of Mn doping on the microstructure and electrical properties of PBZ thin films were investigated systemically. X-ray diffraction patterns showed that both films had a polycrystalline perovskite structure, and that the degree of (111) orientation were increased by Mn doping. Dielectric measurements illustrated that Mn-doped PBZ thin films not only had a larger dielectric constant, but also possessed a smaller dielectric loss. Accordingly, the tunability and the figure of merit of PBZ films were improved by Mn doping.
[Show abstract][Hide abstract] ABSTRACT: In present work, (Pb0.5Ba0.5)ZrO3 (PBZ) thin films with a thickness of 840 nm were successfully fabricated on (Sr0.95La0.05)TiO3 (SLT) buffer-layered Pt(1 1 1)/TiO2/SiO2/Si(1 0 0) substrates via the sol–gel technique. The effects of SLT buffer layer on the microstructure and electrical properties of PBZ thin films were investigated systemically. X-ray diffraction (XRD) and scanning electron microscopy (SEM) results indicated that PBZ thin films on SLT buffer-layered substrates showed a more uniform structure with a random orientation. Dielectric measurements illustrated that PBZ films with SLT buffer layer displayed larger dielectric constant, improved tunability and enhanced figure of merit (FOM). Moreover, leakage current of PBZ films was also reduced by SLT buffer layer.