An Effective Way to Suppress the Pyrochlore Phase Formation in SBT Thin Films

2003 ◽  
Vol 784 ◽  
Author(s):  
Se-Yeon Jung ◽  
Woo-Chul Kwak ◽  
Seung-Joon Hwang ◽  
Yun-Mo Sung
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Seed Layer ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Energy Difference ◽  
Ion Diffusion ◽  
Aurivillius Phase ◽  
Si Substrates ◽  
Coating Methods

ABSTRACTSr0.7Bi2.4Ta2O9 (SBT) thin films were deposited on Pt/Ti/SiO2/Si substrates with and without a seed layer of ∼40 nm thickness using sol-gel and spin coating methods. The influence of seed layer on the phase formation characteristics of SBT thin films was investigated using x-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Formation of pyrochlore as well as Aurivillius phase was observed in both the unseeded and seeded SBT films heated at 740°C. However, it was revealed that Aurivillius phase formation was enhanced in seeded SBT thin films and pyrochlore phase formation was highly suppressed. In this study, two possible mechanisms for the suppression of pyrochlore phase formation were proposed from the perspectives of activation energy difference for Aurivillius and pyrochlore phase formation and Bi-ion diffusion to pyrochlore phase.

Suppression of pyrochlore phase formation in Sr0.7Bi2.4Ta2O9 thin films using nanoseed layer

2003 ◽  
Vol 18 (8) ◽  
pp. 1745-1748 ◽  
Author(s):  
Se-Yeon Jung ◽  
Seung-Joon Hwang ◽  
Yun-Mo Sung
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Seed Layer ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Energy Difference ◽  
Ion Diffusion ◽  
Aurivillius Phase ◽  
Si Substrates ◽  
Coating Methods

A Sr0.7Bi2.4Ta2O9 (SBT) seed layer approximately 40 nm thick was formed on Pt/Ti/SiO2/Si substrates, and SBT thin films with the same chemical composition were deposited on the substrates with and without seed layer using sol-gel and spin coating methods. The influence of seed layer on the phase formation characteristics of SBT thin films was investigated using x-ray diffraction and scanning electron microscopy analyses. Formation of pyrochlore as well as Aurivillius phase was observed in both the unseeded and seeded SBT films heated at 740 °C. However, it was revealed that Aurivillius phase formation was enhanced in seeded SBT thin films and pyrochlore phase formation was highly suppressed. In this study, two possible mechanisms for the suppression of pyrochlore phase formation were proposed from the perspectives of activation energy difference between Aurivillius and pyrochlore phase formation, and Bi-ion diffusion to pyrochlore phase.

Influence of nanoparticle seeding on the phase formation kinetics of sol-gel-derived Sr0.7Bi2.4Ta2O9 thin films

2003 ◽  
Vol 18 (2) ◽  
pp. 387-395 ◽  
Author(s):  
Yun-Mo Sung ◽  
Gopinathan M. Anilkumar ◽  
Seung-Joon Hwang
Keyword(s):  
Thin Films ◽  
Phase Transformation ◽  
Phase Formation ◽  
Volume Fraction ◽  
Sol Gel ◽  
Fluorite Phase ◽  
Microstructural Development ◽  
Aurivillius Phase ◽  
Si Substrates ◽  
Formation Kinetics

Sr0.7Bi2.4Ta2O9 (SBT) thin films were deposited on unseeded and SBT nanoparticle (approximately 60–80 nm) seeded Pt/Ti/SiO2Si substrates via sol-gel and spin-coating techniques. The SBT thin films were heated at 600 °C for 1 h to form the fluorite phase, and these fluorite films were further heated at 730–760 °C for fluorite-to-Aurivillius phase transformation. The volume fractions of Aurivillius phase formation obtained through quantitative x-ray diffraction analyses showed highly enhanced kinetics in seeded SBT thin films. Johnson–Mehl–Avrami isothermal kinetic analyses were performed for the characterization of Aurivillius phase formation in unseeded and seeded SBT thin films using the volume fraction values. The Avrami exponents were determined as approximately 1.4 and approximately 0.9 for unseeded and seeded SBT films, respectively, which reveals different nucleation modes. By using Arrhenius-type plots, the activation energy values for the phase transformation of unseeded and seeded SBT thin films were determined to be approximately 264 and approximately 168 kJ/mol, respectively. This gives a key reason for the enhanced kinetics in seeded films. Microstructural analyses on unseeded SBT thin films showed formation of randomly oriented needlelike crystals, while those on seeded ones showed formation of domains comprising directionally grown wormlike crystals. On the basis of the phase formation kinetics and microstructural development, a model representing different nucleation and crystal growth mechanisms for the unseeded and seeded SBT thin films was proposed.

Enhancement of Aurivillius Phase Formation Kinetics in SBT Thin Films using Nanoparticle Seeding

2003 ◽  
Vol 784 ◽  
Author(s):  
Yun-Mo Sung ◽  
Woo-Chul Kwak ◽  
Se-Yon Jung ◽  
Seung-Joon Hwang
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Phase Transformation ◽  
Phase Formation ◽  
X Ray Diffraction ◽  
Aurivillius Phase ◽  
X Ray ◽  
Si Substrates ◽  
Formation Kinetics ◽  
Kinetics Of

ABSTRACTPt/Ti/SiO2/Si substrates seeded by SBT nanoparticles (∼60–80 nm) were used to enhance the phase formation kinetics of Sr0.7Bi2.4Ta2O9 (SBT) thin films. The volume fractions of Aurivillius phase formation obtained through quantitative x-ray diffraction (Q-XRD) analyses showed highly enhanced kinetics in seeded SBT thin films. The Avrami exponents were determined as ∼1.4 and ∼0.9 for unseeded and seeded SBT films, respectively, which reveals different nucleation modes. By using Arrhenius–type plots the activation energy values for the phase transformation of unseeded and seeded SBT thin films were determined to be ∼264 and ∼168 kJ/mol, respectively. This gives a key reason to the enhanced kinetics in seeded films. Microstructural analyses on unseeded SBT thin films showed formation of randomly oriented needle-like crystals, while those on seeded ones showed formation of domains comprised of directionally grown worm-like crystals.

Secondary Phase Formation and Microstructural Development in the Interaction Between SrBi2Ta2O9 Films and Pt/Ti/SiO2/Si Substrates

1997 ◽  
Vol 12 (8) ◽  
pp. 2104-2110 ◽  
Author(s):  
Chung-Hsin Lu ◽  
Buh-Kuan Fang
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Spin Coating ◽  
Pyrochlore Phase ◽  
Pyrochlore Structure ◽  
Secondary Phase ◽  
Microstructural Development ◽  
Titanium Layer ◽  
Si Substrates ◽  
Secondary Phase Formation

The phase formation and microstructural development of SrBi2Ta2O9 thin films prepared via spin-coating using metalorganic solution on Pt/Ti/SiO2/Si substrates have been investigated in this study. The spun-on films started to crystallize from above 550 °C and were well crystallized at 800 °C. At higher than 850 °C a secondary phase having a pyrochlore structure was formed in the films. The analysis of EDS and SIMS confirmed that the interaction between the films and the titanium species which diffused outward from the titanium layer on substrates was the origin for the occurrence of the pyrochlore phase. In addition, varying the thickness of the coated films and platinum layers had remarkable influence on the formation amount of the pyrochlore phase.

Giant piezoelectric properties of BZT–0.5BCT thin films induced by nanodomain structure

RSC Advances ◽  
2014 ◽  
Vol 4 (100) ◽  
pp. 56933-56937 ◽  
Author(s):  
W. L. Li ◽  
T. D. Zhang ◽  
Y. F. Hou ◽  
Y. Zhao ◽  
D. Xu ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Seed Layer ◽  
Piezoelectric Properties ◽  
Sol Gel ◽  
Si Substrates ◽  
Gel Technique ◽  
Nanodomain Structure

Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 (BZT–0.5BCT) thin films were prepared from two ceramics targets, Ba(Zr0.2Ti0.8)O3 and (Ba0.7Ca0.3)TiO3, using dual-magnetron sputtering, and a LaNiO3 (LNO) seed layer was introduced between the film and Pt(111)/Ti/SiO2/Si substrates via a sol–gel technique.

Phase transition and piezoelectricity of sol–gel-processed Sm-doped BiFeO3 thin films on Pt(111)/Ti/SiO2/Si substrates

2015 ◽  
Vol 3 (9) ◽  
pp. 2115-2122 ◽  
Author(s):  
Wei Sun ◽  
Jing-Feng Li ◽  
Qi Yu ◽  
Li-Qian Cheng
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Sol Gel ◽  
Orthorhombic Phase ◽  
High Quality ◽  
Si Substrates ◽  
Bifeo3 Thin Films ◽  
Gel Processing

We prepared high-quality Bi1−xSmxFeO3 films on Pt(111)/Ti/SiO2/Si substrates by sol–gel processing and found rhombohedral–orthorhombic phase transition with enhanced piezoelectricity.

Synthesis and Ferroelectric Properties of Sol–Gel Derived Intergrowth-Superlattice-Structured SrBi4Ti4O15-Bi4Ti3O12 Thin Films

2011 ◽  
Vol 197-198 ◽  
pp. 1781-1784
Author(s):  
Hua Wang ◽  
Jian Li ◽  
Ji Wen Xu ◽  
Ling Yang ◽  
Shang Ju Zhou
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Annealing Temperature ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Si Substrates ◽  
Gel Processing ◽  
Coercive Electric Field ◽  
Clockwise Hysteresis

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.

A Study on the Piezoelectric Properties of PZT and Doped PZT Thin Films by Sol-Gel Method

2010 ◽  
Vol 663-665 ◽  
pp. 650-653
Author(s):  
Jin Moo Byun ◽  
Jeong Sun Han ◽  
Jae Hyoung Park ◽  
Seong Eui Lee ◽  
Hee Chul Lee
Keyword(s):  
Thin Films ◽  
Piezoelectric Coefficient ◽  
Energy Harvester ◽  
Sol Gel ◽  
Pure Perovskite Structure ◽  
Pzt Thin Films ◽  
Gel Method ◽  
Sol Gel Method ◽  
Si Substrates ◽  
Pzt Thin Film

This study examined the effect of crystalline orientation and dopants such as Nb and Zn on the piezoelectric coefficient of sol-gel driven Pb1(Zr0.52Ti0.48)O3(PZT) and doped PZT thin films. Crack-free 1-μm-thick PZT and doped PZT thin films prepared by using 2-Methoxyethanol-based sol-gel method were fabricated on Pt/Ti/SiO2/Si substrates. The highly (111) oriented PZT thin films of pure perovskite structure could be obtained by controlling various parameters such as a PbTiO3 seed layer and a concentration of sol-gel solution. The Nb-Zn doped PZT thin films exhibited high piezoelectric coefficient which was about 50 % higher than that of undoped PZT thin film. The highest measured piezoelectric coefficient was 240 pC/N, which could be applicable to piezoelectrically operated MEMS actuator, sensor, or energy harvester devices.

scholarly journals Interfacial mechanisms controlling phase formation in sol-gel derived lead zirconate titanate thin films

1994 ◽  
Vol 17 (6) ◽  
pp. 1005-1014 ◽  
Author(s):  
S B Majumder ◽  
V N Kulkarni ◽  
Y N Mohapatra ◽  
D C Agrawal
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Zirconate Titanate

Effects of Sputter-Deposited LaNiO3 Electrode on the Deposition and Properties of Ferroelectric Thin Films

1996 ◽  
Vol 433 ◽  
Author(s):  
T. B. Wu ◽  
J. M. Wu ◽  
C. M. Wu ◽  
M. J. Shyu ◽  
M. S. Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Processing Condition ◽  
Fatigue Property ◽  
Rf Magnetron Sputtering ◽  
Ferroelectric Films ◽  
Si Substrates ◽  
Sputter Deposited

AbstractHighly (100)-textured thin film of metallic LaNiO3 (LNO) was grown on the Pt/Ti/SiO2/Si substrates by rf magnetron sputtering at ˜300°C, which was used as a bottom electrode to prepare highly (100)-textured ferroelectric films. Examples on the deposition of PbTiO3, (Pbl−xLax)TiO3, Pb(Zr0.53Ti0.47)O3, Pb[(Mg1/3Nb2/3)1−xTix]O3, and (Ba1−xSrx)TiO3 thin films by rf magnetron sputtering or sol-gel method are shown. A reduction of temperature for perovskite phase formation can be achieved, especially for those difficult to crystallize. The surface roughness of the ferroelectric films is also improved as compared to that of films deposited on conventional Pt electrode. Although the electrical properties of the ferroelectric films are affected by the out-diffusion of LNO when a higher temperature was used in the preparation of the films, under an appropriate processing condition, the highly (100)-textured films can have satisfactory electrical characteristics for application. Moreover, the polarization-fatigue property can be also improved by the use of LNO electrode.

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