STRUCTURE CONTROL AND FERROELECTRIC PROPERTIES OF SrBi4Ti4O15 THIN FILMS ON Si SUBSTRATES COATED BY (100)- AND (110)-ORIENTED LaNiO3 ELECTRODES

2007 ◽  
Vol 14 (03) ◽  
pp. 435-438
Author(s):  
PILONG WANG ◽  
GUANGDA HU ◽  
YANXIA DING ◽  
SUHUA FAN

SrBi 4 Ti 4 O 15 ( SBTi ) thin films were prepared on (100)- and (110)-oriented LaNiO 3( LNO ) electrodes by a metalorgranic decomposition (MOD) technique at an annealing temperature of 650°C. c-axis-oriented SBTi thin film with volume fraction of 0.89 can be formed on a (100)-oriented LNO film due to the epitaxial relationship between c-axis-oriented SBTi and LNO (100). In contrast, SBTi film deposited on LNO (110) shows random orientations with strong (119) and (200) peaks. The remanent polarization (Pr) and coercive field (Ec) of the random oriented SBTi film were 18.1 μC/cm2 and 70 kV/cm, respectively. This suggests that (110)-oriented LNO electrode is a better choice for obtaining SBTi films with higher volume fraction of a(b)-axis-orientated grains.

2008 ◽  
Vol 368-372 ◽  
pp. 100-102 ◽  
Author(s):  
Su Hua Fan ◽  
Jing Xu ◽  
Guang Da Hu ◽  
Bo He ◽  
Feng Qing Zhang

Ca1-xSrxBi4Ti4O15 thin films were fabricated by sol-gel method on Pt(100)/Ti/SiO2/Si substrates. Influence of Sr content on the microstructure and ferroelectric properties of Ca1-xSrxBi4Ti4O15 thin films were systematically studied. The results indicate that Ca0.4Sr0.6Bi4Ti4O15 thin film has better ferroelectric properties with remanent polarization (2Pr) of 29.1+C/cm2, coercive field (2Ec) of 220 kV/cm. Furthermore, the film has good fatigue resistance. The better ferroelectric properties of Ca0.4Sr0.6Bi4Ti4O15 thin film originate from the relatively high concentration of a-axis oriented grains.


2011 ◽  
Vol 197-198 ◽  
pp. 1781-1784
Author(s):  
Hua Wang ◽  
Jian Li ◽  
Ji Wen Xu ◽  
Ling Yang ◽  
Shang Ju Zhou

Intergrowth-superlattice-structured SrBi4Ti4O15–Bi4Ti3O12(SBT–BIT) films prepared on p-Si substrates by sol-gel processing. Synthesized SBT–BIT films exhibit good ferroelectric properties. As the annealing temperature increases from 600°C to 700°C, the remanent polarization Prof SBT–BIT films increases, while the coercive electric field Ecdecreases. SBT–BIT films annealed at 700°C have a Prvalue of 18.9µC/cm2which is higher than that of SBT (16.8µC/cm2) and BIT (14.6µC/cm2), and have the lowest Ecof 142 kV/cm which is almost the same as that of SBT and BIT. The C-V curves of Ag/SBT-BIT/p-Si heterostructures show the clockwise hysteresis loops which reveal the memory effect due to the polarization. The memory window in C-V curve of Ag/SBT-BIT/p-Si is larger than that of Ag/SBT/p-Si heterostructure or Ag/BIT/p-Si heterostructure.


2005 ◽  
Vol 902 ◽  
Author(s):  
Sushil Kumar Singh ◽  
Hiroshi Ishiwara

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.


2007 ◽  
Vol 21 (18n19) ◽  
pp. 3404-3411
Author(s):  
M. C. KAO ◽  
H. Z. CHEN ◽  
S. L. YOUNG ◽  
C. C. LIN ◽  
C. C. YU

LiTaO 3 thin films were deposited on Pt / Ti / SiO 2/ Si substrates by means of a sol-gel spin-coating technology and rapid thermal annealing (RTA). The influence of various annealing treatments on the characteristics of the thin films were studied by varying the single-annealed-layer thickness (50 ~ 200 nm ) and heating temperatures (500 ~ 800° C ) of the samples. Experimental results reveal that the single-annealed-layer strongly influences grain size, dielectricity and ferroelectricity of LiTaO 3 thin films. The grain size of LiTaO 3 thin film decreases slightly with increasing thickness of the single-annealed-layer, and highly c-axis orientated LiTaO 3 films can be obtained for a single-annealed-layer of 50 nm. When the thickness of the single-annealed-layer was increased from 50 to 200 nm, the relative dielectric constant of LiTaO 3 thin film decreased from 65 to 35, but the dielectric loss factor (tanδ) was increased. The LiTaO 3 films with the single-annealed-layer of 50 nm showed excellent ferroelectric properties in terms of a remanent polarization ( P r) of 12.3 μ C /cm2 (Ec ∼ 60 kV/cm), and a low current density of 5.2×l0-8 A /cm2 at 20 kV/cm.


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.


2010 ◽  
Vol 434-435 ◽  
pp. 296-299
Author(s):  
Jian Ping Yang ◽  
Xing Ao Li ◽  
An You Zuo ◽  
Zuo Bin Yuan ◽  
Zhu Lin Weng

Bi4Ti3O12 (BTO) and Bi3.25La0.75Ti3O12 (BLT) ferroelectric thin films were deposited on Pt/Si substrates by RF magnetron sputtering with Bi4Ti3O12 (BTO) and Bi3.25La0.75Ti3O12 (BLT) targets with 50-mm diameter and 5-mm thickness. The microstructure and ferroelectric properties of thin films were investigated. The grain growth behavior and ferroelectric properties such as remanent polarization were different in these two kinds of film, the effects of La doping in the BLT thin film were very obvious.


2008 ◽  
Vol 368-372 ◽  
pp. 91-94
Author(s):  
S. Chen ◽  
A.H. Cai ◽  
X.A. Mei ◽  
Chong Qing Huang ◽  
W.K. An ◽  
...  

Sm-doped bismuth titanate and random oriented Bi4-xCexTi3O12 (BCT) thin films were fabricated on Pt/Ti/SiO2/Si substrates rf magnetron sputtering technique. The structures and the ferroelectric properties of the films were investigated. Ce doping leads to a marked improvement in the remanent polarization (Pr) and the coercive field (Ec). At the applied electric field of 100 kV/cm, Pr and Ec of the BCT (x = 0.8) film annealed at 650 oC are 20.5 μC/cm2 and 60 KV/cm, respectively. However, after 3 × 1010 switching cycles, 20% degradation of 2Pr is observed in the film.


2002 ◽  
Vol 718 ◽  
Author(s):  
Ching-Chich Leu ◽  
Chao-Hsin Chien ◽  
Ming-Jui Yang ◽  
Ming-Che Yang ◽  
Tiao-Yuan Huang ◽  
...  

AbstractThe effects of a seeding layer, which was deposited on Pt/TiO2/SiO2/Si substrates using magnetron sputtering, on the characteristics of sol-gel-deposited strontium-bismuth-tantalate (SBT) thin films are investigated. The seeding layer serves as nucleation sites so homogeneous crystalline SBT films of bismuth-layered structure (BLS) with fine grains are successfully obtained by 750°C rapid thermal annealing in O2 ambient. The remanent polarization (2Pr) improves from 12.1 to 18.8 μC/cm2 with the addition of the seeding layer. In addition, the seeding layer also results in a lower nucleation temperature, allowing the use of 700°C annealing for 10 min to grow SBT films that are fully crystallized with BLS phase and shows good ferroelectric properties. Finally, crystallinity and microstructures of SBT films are found to be strongly dependent on the thickness of the seeding layer. Optimum Ta-seeded SBT thin film crystallized at 700°C for 10min depicts a higher 2Pr value (12.9 μC/cm2 (@5V) than that of the un-seeded films crystallized at 750°C for 1min.


2014 ◽  
Vol 633 ◽  
pp. 378-381
Author(s):  
Bei Li ◽  
X.B. Liu ◽  
M. Chen ◽  
X.A. Mei

Dy-doped Bi4Ti3O12 thin films were fabricated on Pt/Ti/SiO2/Si substrates by pulsed laser deposition technique, and the structures and electrical properties of the films were investigated. XRD results indicated that all of Bi4-xDyxTi3O12 films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. The remanent polarization ( Pr ) and coercive field (Ec) of the Bi4-xDyxTi3O12 Film with x=0.75 were 25μC/cm2 and 85KV/cm , respectively.


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.


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