Influence of Ta content on the physical properties of SrBi2Ta2O9 ferroelectric thin films

2006 ◽  
Vol 21 (12) ◽  
pp. 3124-3133 ◽  
Author(s):  
Fan-Yi Hsu ◽  
Ching-Chich Leu ◽  
Chao-Hsin Chien ◽  
Chen-Ti Hu
Keyword(s):  
Thin Films ◽  
Physical Properties ◽  
Spin Coating ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Ferroelectric Thin Films ◽  
Preferential Orientation ◽  
Strontium Bismuth Tantalate ◽  
Metalorganic Decomposition

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.

Ferroelectric Characteristics of SrxBi2.4Ta2O9 Thin Films and Electrical Properties of the Pt/SrxBi2.4Ta2O9/TiO2/Si Structure

2004 ◽  
Vol 449-452 ◽  
pp. 477-480
Author(s):  
J.H. Choi ◽  
Tae Sung Oh
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Memory Window ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Metalorganic Decomposition ◽  
Ferroelectric Hysteresis

Ferroelectric characteristics of the 400 nm-thick SrxBi2.4Ta2O9(0.7≤x≤1.3) thin films processed by metalorganic decomposition were investigated, and electrical properties of the Pt/Sr0.85Bi2.4Ta2O9/TiO2/Si structure prepared using TiO2 buffer layer were characterized. The Sr-deficient SrxBi2.4Ta2O9 films exhibited well-developed ferroelectric hysteresis curves compared to those of the Sr-excess films. The Sr0.85Bi2.4Ta2O9 film exhibited optimum ferroelectric properties, such as high remanent polarization and low leakage current density, among SrxBi2.4Ta2O9 films. A memory window of the Pt/SrxBi2.4Ta2O9/TiO2/Si structure was dependent upon the coercive field of the SrxBi2.4Ta2O9 film, and the Pt/SrxBi2.4Ta2O9/TiO2/Si exhibited a maximum memory window of 1.3 V at the sweeping voltage of ±5 V.

Ti-site Substitution Using the Higher-valent Cation for Enhancing the Ferroelectric Properties of Nd3+−substituted Bismuth Titanate Thin Films

2003 ◽  
Vol 784 ◽  
Author(s):  
Hiroshi Uchida ◽  
Seiichiro Koda ◽  
Hirofumi Matsuda ◽  
Takashi Iijima ◽  
Takayuki Watanabe ◽  
...  
Keyword(s):  
Thin Films ◽  
Coercive Field ◽  
Chemical Solution Deposition ◽  
Remanent Polarization ◽  
Bismuth Titanate ◽  
Ferroelectric Properties ◽  
Ferroelectric Thin Films ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Si Substrates

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.

EFFECT OF GRAIN SIZE ON THE FERROELECTRIC PROPERTIES OF Bi3.25La0.75Ti3O12 Thin Films

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4469-4474 ◽  
Author(s):  
KYOUNG-TAE KIM ◽  
CHANG-IL KIM ◽  
DONG-HEE KANG ◽  
IL-WUN SHIM
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Fatigue Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Current Densities ◽  
Metalorganic Decomposition ◽  
Small Grains

The Bi 3.25 La 0.75 Ti 3 O 12 (BLT) thin films were prepared by metalorganic decomposition method. The effect of grain size on the ferroelectric properties during crystallization were investigated by x-ray diffraction and field emission scanning electron microscope. The grain size and the roughness of BLT films increase with increasing of drying temperature. The leakage current densities of the BLT thin film with large grains are higher than that with small grains. The remanent polarization of BLT increase with increasing grain size. As compared BLT with small grain size, the BLT film with larger grain size shows better fatigue properties. This may be explained that small grained films shows more degradation of switching charge than large grained films.

The role of nanoporosity on the local piezo and ferroelectric properties of lead titanate thin films

2015 ◽  
Vol 3 (5) ◽  
pp. 1035-1043 ◽  
Author(s):  
Alichandra Castro ◽  
Paula Ferreira ◽  
Brian J. Rodriguez ◽  
Paula M. Vilarinho
Keyword(s):  
Thin Films ◽  
Coercive Field ◽  
Lead Titanate ◽  
Ferroelectric Properties ◽  
Ferroelectric Thin Films ◽  
Piezoelectric Response ◽  
Nanoporous Films ◽  
Switching Behaviour ◽  
Dense Films

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.

0.75SrBi2Ta2O9-0.25Bi3TiTaO9 Layered Structural Thin Films: Microstructure and Ferroelectric Properties

2008 ◽  
Vol 368-372 ◽  
pp. 1814-1816
Author(s):  
Dan Xie ◽  
Zhi Gang Zhang ◽  
Tian Ling Ren ◽  
Li Tian Liu
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Grain Size ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Significant Enhancement ◽  
Solution Deposition ◽  
Annealing Temperatures

{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.

Enhanced Electrical properties in Mn-doped Bi3.25La0.75Ti3O12 thin films

2005 ◽  
Vol 902 ◽  
Author(s):  
Sushil Kumar Singh ◽  
Hiroshi Ishiwara
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Switching Field ◽  
Mn Doping ◽  
Mn Doped

AbstractMn-doped Bi3.25La0.75Ti3O12 (BLT) thin films were fabricated by depositing sol-gel solutions on Pt/Ti/SiO2/Si <100> substrates. The surface morphology and ferroelectric properties of Mn-doped BLT films depend upon the orientation of the films. Small amount of Mn-doping in BLT films influences the ferroelectric properties of the films, that is, it enhances the remanent polarization and reduces the coercive field. The 1% Mn-doped BLT films show enhanced remanent polarization and reduced the coercive field by about 22%. To the contrary, Mn-doping more than 1% decreases polarization gradually. Mn-doping significantly improves the fatigue resistance of BLT films. The reduced polarization in the 3.3% Mn-doped thin film recovers during switching cycles higher than 5 × 105. Under high switching field, the probability of field-assisted unpinning of domains is expected to be high and this may be the main cause for increase in polarization after 5 × 105 in the 3.3% Mn-doped BLT film.

Composition Dependence of Dielectric Anomaly in Strontium Bismuth Tantalate Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
Koichi Takemura ◽  
Takehiro Noguchi ◽  
Takashi Hase ◽  
Hidekazu Kimura ◽  
Yoichi Miyasaka
Keyword(s):  
Thin Films ◽  
Temperature Dependence ◽  
Local Structure ◽  
Remanent Polarization ◽  
Composition Dependence ◽  
Lattice Structure ◽  
Ferroelectric Properties ◽  
Dielectric Anomaly ◽  
Strontium Bismuth Tantalate ◽  
First Order

AbstractEffects of off-stoichiometry and Nb substitution on the dielectric anomaly and ferroelectric properties have been investigated for SrBi2Ta2O9(SBT) thin films. Local atomic environment for the stoichiometric and off-stoichiometric SBT films has been also measured. The features of the dielectric anomaly, the Curie temperature (Tc), and the temperature dependence of the spontaneous polarization (Ps) are independent of the film thickness, and are governed by the nature of the crystal. For the stoichiometric Sr content SBT films, the grain size increases and the temperature dependence of the remanent polarization (Pr) decreases with increasing thickness. For the films with Sr/Bi/Ta = 0.8/2/2 and 0.8/2.2/2, Sr deficient local structure was observed, and such lattice structure probably leads to higher Tc than the stoichiometric crystal. Nb substitution for Ta also raises Tc, and makes the dielectric anomaly sharper. The phase transition associated with the dielectric anomaly for these films is thought to be first-order.

Preparation and Properties of ferroelectric Bi2SrTa2O9 thin films for FeRAM using Flash-MOCVD

1995 ◽  
Vol 415 ◽  
Author(s):  
T. Ami ◽  
K. Hironaka ◽  
C. Isobel ◽  
N. Nagel ◽  
M. Sugiyama ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Type Structure ◽  
Structural And Electrical Properties ◽  
Fluorite Type ◽  
Deposited Films ◽  
Flowing Oxygen

ABSTRACTFerroelectric Bi2 SrTa2 O9 thin films were successfully prepared by liquid delivery MOCVD, and structural and electrical properties were investigated. As-deposited films showed sharp distinct peaks, which were indexed assuming a fluorite-type structure. These precursors were transformed to bismuth-layered structures by annealing at 800 °C in flowing oxygen. Reasonable ferroelectric properties were observed in a film with 170 nm-thickness. Remanent polarization and coercive field were estimated to be 5.2 μC/cm2 and 52 kV/cm, respectively, at 5V.

Microstructure and Properties of A-Site Doping Bi4-xYxTi3O12 Ferrroelectric Thin Films

2015 ◽  
Vol 815 ◽  
pp. 171-175
Author(s):  
Hong Cheng Liu ◽  
Wei Jun Zhang ◽  
Xiao Chen Zhang ◽  
Qian Yu ◽  
Jue Wang
Keyword(s):  
Thin Films ◽  
Coercive Field ◽  
Remnant Polarization ◽  
Bismuth Titanate ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Ferroelectric Thin Films ◽  
Phase Development ◽  
Sol Gel Process ◽  
A Site

s. Yttium-substituted bismuth titanate (Bi4-xYxTi3O12, BYT) thin films were deposited on the (111)Pt/Ti/SiO2(100) substrates by a modified Sol-Gel process and studied in this work in terms ofY3+-modified microstructure and phase development as well as ferroelectric properties. With the aid of the fist-principle, the position of Y3+substitution for Bi3+on the microstructure of BYT was studied.The phase change in the formation of BYT crystalline and the effect of Y3+substitution for Bi3+on the microstructure of BYT was studiedbyXRD. The results showed that the optimal properties of the obtained BYT ferroelectric thin films werex:0.6. The ferroelectric properties of the films were also investigated. When the Y-substituted contentxwas equal to 0.6, the remnant polarization was the largest. The remnant polarization 2Prvalue was equal to 16.02μC/cm2and the coercive fieldEcvalue was 88 kV/cm.

Electrical Characteristics in Transparent (Bi3.25Nd0.75)(Ti2.9V0.1)O12 Ferroelectric Thin Films

2014 ◽  
Vol 602-603 ◽  
pp. 777-780
Author(s):  
Fann Wei Yang ◽  
Chien Min Cheng ◽  
Kai Huang Chen
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Ferroelectric Thin Film ◽  
Rf Magnetron Sputtering ◽  
Ferroelectric Thin Films ◽  
Electrical Characteristics ◽  
X Ray Diffraction ◽  
Film Capacitor ◽  
X Ray

In this study, we investigated the structure and ferroelectric properties of the as-deposited (Bi3.25Nd0.75)(Ti2.9V0.1)O12ferroelectric thin films on ITO substrate fabricated by rf magnetron sputtering method. The electrical, ferroelectric and physical characteristics of as-deposited (Bi3.25Nd0.75)(Ti2.9V0.1)O12thin films were developed under different conditions to find the optimal deposited parameters. The crystalline structure of the prepared (Bi3.25Nd0.75)(Ti2.9V0.1)O12thin films was analyzed by X-ray diffraction (XRD). Field emission scanning electron microscopy (FESEM) was used to observe the film thickness and the surface morphology including grain size and porosity. Additionally, the remnant polarization of the as-deposited ferroelectric thin films was improved by neodymium and vanadium elements doped in this study. The remanent polarization of as-deposited ferroelectric thin films was 11 μC/cm2as the measured frequency of 1kHz. Finally, the polarization of as-deposited ferroelectric thin film capacitor was decreased by 9% after the fatigue test with 109switching cycles.

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