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.

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.

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.

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.

scholarly journals Study of obtaining thin films of CeO2 doped with 2 and 4 mol% of europium, terbium and thulium by spin coating: photocatalytic properties

Cerâmica ◽  
2019 ◽  
Vol 65 (376) ◽  
pp. 515-522
Author(s):  
B. P. Dias ◽  
N. F. Andrade Neto ◽  
L. M. P. Garcia ◽  
M. R. D. Bomio ◽  
F. V. Motta
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Spin Coating ◽  
Secondary Phase ◽  
Blue Dye ◽  
Surface Porosity ◽  
Secondary Phase Formation ◽  
Doped Ceo2 ◽  
Xrd Patterns

Abstract In this study, thin films of Eu3+, Tb3+ and Tm3+ doped CeO2 in the proportions of 2 and 4 mol% were obtained by spin coating and calcined at 700 °C. The films were characterized by XRD, SEM, AFM and UV-vis techniques. The photocatalytic activity of the thin films was measured by the degradation of the methylene blue (MB) dye. The thin films were submitted to 4 photocatalytic cycles to analyze the capacity to be reused. XRD patterns showed no secondary phase formation, where all characteristic peaks were related to CeO2. SEM micrographs indicated that doping at 4 mol% promoted the reduction in the thickness and surface porosity of the thin films. AFM images indicated the increase in surface roughness with rare earths doping. Doping with Eu3+, Tb3+ and Tm3+ increased the degradation of the methylene blue dye by at least 15% for thin films doped at 4 mol%. The reuse tests indicated that the photocatalytic activity remained practically constant even with the application of four consecutive cycles.

Electrical properties of sprayed Cu2ZnSnS4 thin films and its relation with secondary phase formation and solar cell performance

2015 ◽  
Vol 132 ◽  
pp. 557-562 ◽  
Author(s):  
O. Vigil-Galán ◽  
Maykel Courel ◽  
M. Espindola-Rodriguez ◽  
D. Jiménez-Olarte ◽  
M. Aguilar-Frutis ◽  
...  
Keyword(s):  
Thin Films ◽  
Solar Cell ◽  
Electrical Properties ◽  
Phase Formation ◽  
Secondary Phase ◽  
Cell Performance ◽  
Solar Cell Performance ◽  
Secondary Phase Formation

scholarly journals Secondary phase formation in (Ag,Cu)(In,Ga)Se2 thin films grown by three-stage co-evaporation

2017 ◽  
Vol 166 ◽  
pp. 18-26 ◽  
Author(s):  
Lei Chen ◽  
Sina Soltanmohammad ◽  
JinWoo Lee ◽  
Brian E. McCandless ◽  
William N. Shafarman
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Secondary Phase ◽  
Secondary Phase Formation

Effect of heating rate and precursor composition on secondary phase formation during Cu2ZnSnS4 thin film growth and its properties

2021 ◽  
pp. 139029
Author(s):  
Sagar Agrawal ◽  
Balasubramanian C ◽  
Subroto Mukherjee ◽  
Rinkal Kanani ◽  
Kishore K. Madapu ◽  
...  
Keyword(s):  
Thin Film ◽  
Heating Rate ◽  
Phase Formation ◽  
Film Growth ◽  
Secondary Phase ◽  
Thin Film Growth ◽  
Secondary Phase Formation ◽  
Cu2znsns4 Thin Film ◽  
Precursor Composition

Secondary phase formation by liquid immiscibility in Ca3Ta(Ga1−xAlx)3Si2O14 melt

2019 ◽  
Vol 522 ◽  
pp. 117-124
Author(s):  
Yuki Honda ◽  
Hiromasa Niinomi ◽  
Jun Nozawa ◽  
Junpei Okada ◽  
Satoshi Uda
Keyword(s):  
Phase Formation ◽  
Secondary Phase ◽  
Liquid Immiscibility ◽  
Secondary Phase Formation
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