Models for the frequency dependence of coercive field and the size dependence of remanent polarization in ferroelectric thin films

1996 ◽  
Vol 12 (2-4) ◽  
pp. 71-81 ◽  
Author(s):  
J. F. Scott
2006 ◽  
Vol 21 (12) ◽  
pp. 3124-3133 ◽  
Author(s):  
Fan-Yi Hsu ◽  
Ching-Chich Leu ◽  
Chao-Hsin Chien ◽  
Chen-Ti Hu

We have investigated the effect that the Ta content has on the ferroelectric properties of strontium bismuth tantalate (SBT) thin films synthesized using metalorganic decomposition (MOD) and spin coating techniques. The physical properties of these SBT samples were strongly dependent upon the Ta ratio. Polarization measurements revealed that Ta-deficient SBT exhibited a relatively low coercive field (2Ec ∼ 87 kV/cm) and a high remanent polarization (2Pr ∼ 15 μC/cm2). The value of 2Pr decreased as the Ta ratio in SBT increased. The improved ferroelectric properties of the Ta-deficient SBT samples may have resulted from the uniformly well-grown bismuth-layered-structured (BLS) phases of the films and their highly preferential orientation along the a and b axes. We suggest that the incorporation of Ta vacancies plays an important role in enhancing the crystallinities and microstructures of Ta-deficient SBT films.


2009 ◽  
Vol 51 (7) ◽  
pp. 1348-1350 ◽  
Author(s):  
A. S. Sidorkin ◽  
L. P. Nesterenko ◽  
S. V. Ryabtsev ◽  
A. A. Sidorkin

2003 ◽  
Vol 784 ◽  
Author(s):  
Hiroshi Uchida ◽  
Seiichiro Koda ◽  
Hirofumi Matsuda ◽  
Takashi Iijima ◽  
Takayuki Watanabe ◽  
...  

ABSTRACTTi-site substitution using the higher-valent cation was performed on ferroelectric thin films of neodymium-substituted bismuth titanate, (Bi,Nd)4Ti3O12(BNT), in order to improve its ferroelectric properties by compensating the space charge in BIT-based crystal. Ti-site-substituted BNT films, (Bi3.50Nd0.50)1-(x/12)(Ti3.00-xVx)O15(x= 0 ∼ 0.09), were fabricated on (111)Pt/Ti/ SiO2/(100)Si substrates using a chemical solution deposition (CSD) technique. V5+-substitution enhanced the remanent polarization of BNT film without change in the coercive field. V5+-substitution also exhibited the possibilities for improving the endurance against leakage current and fatigue degradation.


2003 ◽  
Vol 780 ◽  
Author(s):  
Rasmi R. Das ◽  
P. Bhattacharya ◽  
W. Pérez ◽  
Ram S. Katiyarxya

AbstractPulsed-laser-deposition technique was used to grow SrBi2Nb2O9(SBN) thin films on platinized silicon substrates. The effect of annealing temperature and film thicknesses on the structural and electrical properties has been studied. The average grain size and rms surface roughness was found to increase with increasing annealing temperature. The degree of orientation along the (200) direction was increased with the film thicknesses. The remanent polarization was found to be increased with the film thicknesses and was attributed to the selftexturing characteristics of SBN films. Thin films with higher thickness (∼570 nm) exhibited high value of remanent polarization (∼38 ν/cm2) with coercive field of 185 kV/cm. There was a reduction of coercive field with the film thickness. The dielectric constant was observed to be independent of the film thickness. The increase in loss tangent with increasing film thicknesses was attributed to the reduction of dielectric breakdown strength of the films. The SBN thin films showed minimal fatigue characteristics and suitable material for memory devices.


2011 ◽  
Vol 415-417 ◽  
pp. 1855-1858
Author(s):  
Wen Cheng Tzou ◽  
Chien Chen Diao ◽  
Chao Chin Chan ◽  
Chia Ching Wu ◽  
Chang Fu Yang ◽  
...  

In this study, SrBi4Ti4O15 (SBT) thin films were deposited onto the SiO2/p-Si(100) and Pt/Ti/SiO2/p-Si(100) substrates by using sol-gel method. After deposition, the SBT thin films were then heated by a rapid thermal annealing (RTA) process conducted in air for 1min at 600-800°C. The surface morphologies and the crystalline structures of the SBT thin films were investigated by using SEM and XRD patterns. The grain sizes increased and the pores decreased with rising RTA temperature. In addition, the coercive field decreased and the remanent polarization and saturation polarization increased with rising RTA temperature. The lnJ-E1/2 curves of the SBT thin films were also investigated to find the leakage current mechanisms correspond either to the Schottky emission or to the Poole-Frenkel emission.


2015 ◽  
Vol 3 (5) ◽  
pp. 1035-1043 ◽  
Author(s):  
Alichandra Castro ◽  
Paula Ferreira ◽  
Brian J. Rodriguez ◽  
Paula M. Vilarinho

Nanoporous PbTiO3 films present enhanced tetragonality at lower temperatures than respective dense films. Moreover, the porosity present in the nanoporous films allows an increase of the local piezoelectric response and a decrease of the local coercive field. As a result, these nanoporous films might be used to improve the switching behaviour of ferroelectric thin films.


2008 ◽  
Vol 368-372 ◽  
pp. 1814-1816
Author(s):  
Dan Xie ◽  
Zhi Gang Zhang ◽  
Tian Ling Ren ◽  
Li Tian Liu

{0.75SrBi2Ta2O9-0.25Bi3TiTaO9}(SBT-BTT) thin films were prepared by the modified metalorganic solution deposition (MOSD) technique. The microstructure and ferroelectric properties of SBTBTT thin films were studied. The SBT-BTT thin films were produced at 750°C. The grain size and surface roughness of SBT-BTT films showed significant enhancement with an increase in annealing temperatures. It is found that SBT-BTT thin films have good ferroelectric properties. The measured remanent polarization values for SBT-BTT, SBT and BTT capacitors were 15, 7.5 and 4.8μC/cm2, respectively. The coercive field for SBT-BTT capacitors was 50kV/cm. More importantly, the polarization of SBT-BTT capacitors only decreased 5% after 1011 switching cycles at a frequency of 1MHz.


1998 ◽  
Vol 541 ◽  
Author(s):  
H. Fujisawa ◽  
S. Nakashima ◽  
M. Shimizu ◽  
H. Niu

AbstractThe grain size of MOCVD-Pb(Zr,Ti)O3 (PZT) thin films was successfully controlled by changing the grain size of Ir bottom electrodes and by changing the growth rate of PZT films. In Ir/PZT/Ir/SiO2/Si capacitors, the grain size of PZT thin films increased from 120 to 240nm as the grain size of bottom Ir electrodes increased from 50 to 200nm. The dielectric constants of PZT thin films increased from 760 to 1440 as the grain size increased from 120 to 240nm. Remanent polarization increased and coercive field decreased as the grain size increased. This dependence of electrical properties on the grain size coincided with that of ceramics.


2009 ◽  
Vol 1199 ◽  
Author(s):  
Jeong Hwan Kim ◽  
Hiroshi Funakubo ◽  
Yoshihiro Sugiyama ◽  
Hiroshi Ishiwara

AbstractWe deposited BiFeO3 (BFO) thin films on SrRuO3 (SRO)/Pt bottom electrodes by radio-frequency (RF) sputtering. Some samples were formed at the substrate temperature of 550 °C, and others were foremed at 450 °C and post-annealed at 650°C for crystallization. The coercive field in the post-annealed BFO film was smaller than that in the 550°C-deposited BFO film. The coercive field in Mn-doped BiFeO3 (BFMO) films which were deposited at 550 ˚C on SRO/Pt(111) was lower than that in undoped BFO films. Degradation of the remanent polarization was less significant in the post-annealed BFO film.


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