Dielectric, Pyroelectric, and Thermal Properties of Solid Solutions of Ba (Ti,Zr)O3,Ba(Ti,Hf)03, Ba(Ti,Sn) 03 and (Ba,Nd)TiO3

1994 ◽  
Vol 360 ◽  
Author(s):  
K. K. Deb
Keyword(s):  
Grain Size ◽  
Pyroelectric Coefficient ◽  
Dielectric Constants ◽  
Dielectric Losses ◽  
Oxide Ceramics ◽  
Infrared Sensors ◽  
Pzt Thin Films ◽  
Detector Arrays ◽  
Property Modification ◽  
Size Data

AbstractModified BaTiO3 ceramics are candidate materials for infrared sensors in nightvision equipment. Measurements of dielectric constants, dielectric losses, pyroelectric coefficient, and heat capacities as functions of temperature and frequency are performed. Crystallographic and grain size data are also presented. It is shown that additions of these impurities to BaTiO3 alters the temperature of phase transformations and, with it, dielectric and pyroelectric properties. The results of these measurements were compared with those of PZT and PbTiO3 ceramics, which are currently the favoredmaterials for uncooled detector arrays, as well as PbTiO3 and PZT thin films. It is concluded that these oxide ceramics offer the combination of preparative ease of property modification and show good performance at low impurity concentrations.

Control of Grain Size of Pb(Zr,Ti)O3 Thin Films by MOCVD and the Effect of Size on the Electrical Properties

1998 ◽  
Vol 541 ◽  
Author(s):  
H. Fujisawa ◽  
S. Nakashima ◽  
M. Shimizu ◽  
H. Niu
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Grain Size ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Dielectric Constants ◽  
Pzt Thin Films ◽  
Pzt Films

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.

scholarly journals Paleoenvironments from robust loess stratigraphy using high-resolution color and grain-size data of the last glacial Krems-Wachtberg record (NE Austria)

2020 ◽  
Vol 248 ◽  
pp. 106602
Author(s):  
Tobias Sprafke ◽  
Philipp Schulte ◽  
Simon Meyer-Heintze ◽  
Marc Händel ◽  
Thomas Einwögerer ◽  
...  
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Last Glacial ◽  
Size Data ◽  
The Last Glacial

As-Cast Grain Size of Aluminum Alloys Refined by Al-Ti-B Master Alloys

2019 ◽  
Author(s):  
Mark Easton ◽  
David St John ◽  
Prasad Arvind
Keyword(s):  
Grain Size ◽  
Al Alloys ◽  
Good Ability ◽  
Refined Microstructure ◽  
Critical Technology ◽  
Master Alloys ◽  
Near Net Shape ◽  
Empirical Approaches ◽  
Cast Parts ◽  
Size Data

Grain refinement is a critical technology for the successful production of cast parts; whether that be preforms such as extrusion billet or rolling slab, or near net-shape castings. A refined microstructure has many advantages with reduced defects and improved mechanical properties. This article describes the approaches to the prediction of grain size in Al-alloys refined by Al-Ti-B master alloys. Included are empirical approaches based on the generation and analysis of grain size data, the development of analytical equations, and the use of finite element approaches to the prediction of grain sizes. It is clear that researchers have a good ability to predict grain size of Al-alloys grain refined by Al-Ti-B master alloys, although there are still some outstanding challenges, particularly in considering more extreme solidification conditions and poisoning of the master alloys.

Characterization of Highly Textured PZT Thin Films Grown on LaNiO3 Coated Si Substrates by MOCVD

1997 ◽  
Vol 493 ◽  
Author(s):  
C. H. Lin ◽  
B. M. Yen ◽  
Haydn Chen ◽  
T. B. Wu ◽  
H. C. Kuo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Fatigue Behavior ◽  
Chemical Vapor ◽  
Dielectric Constants ◽  
Preferential Orientation ◽  
Organic Chemical ◽  
Pzt Thin Films ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTHighly textured PbZrxTi1−xO3 (PZT) thin films with x= 0-0.6 were grown on LaNiO3 coated Si substrates at 600 °C by metal-organic chemical vapor deposition (MOCVD). The preferred crystalline orientation of PZT thin films with various Zr concentration were characterized by X-ray diffraction (XRD). Microstructures were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The dielectric constants, hysteresis and fatigue behavior of these thin films were also measured. The relationship between growth rate and the preferential orientation is discussed. Furthermore, the dependence of the electrical properties on Zr concentration and preferential orientation is demonstrated.

Sedimentary environment prediction of grain-size data based on machine learning approach

2020 ◽  
Vol 8 (3) ◽  
pp. SL71-SL78
Author(s):  
Qiao Su ◽  
Yanhui Zhu ◽  
Fang Hu ◽  
Xingyong Xu
Keyword(s):  
Machine Learning ◽  
Grain Size ◽  
Prediction Model ◽  
Sedimentary Environment ◽  
Machine Learning Algorithms ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Data Set ◽  
Sedimentary Environments ◽  
Size Data

Grain size is one of the most important records for sedimentary environment, and researchers have made remarkable progress in the interpretation of sedimentary environments by grain size analysis in the past few decades. However, these advances often depend on the personal experience of the scholars and combination with other methods used together. Here, we constructed a prediction model using the K-nearest neighbors algorithm, one of the machine learning methods, which can predict the sedimentary environments of one core through a known core. Compared to the results of other studies based on the comprehensive data set of grain size and four other indicators, this model achieved a high precision value only using the grain size data. We have also compared our prediction model with other mainstream machine learning algorithms, and the experimental results of six evaluation metrics shed light on that this prediction model can achieve the higher precision. The main errors of the model reflect the length of the conversation area of sedimentary environment, which is controlled by the sedimentary dynamics. This model can provide a quick comparison method of the cores in a similar environment; thus, it may point out the preliminary guidance for further study.

Grain size effect on structures and dielectric constants for nanocrystalline BaTiO3 ceramic

2013 ◽  
Vol 17 (sup1) ◽  
pp. 190-193 ◽  
Author(s):  
L. M. Wang ◽  
X. Y. Deng ◽  
J. B. Li ◽  
G. Q. Zhang ◽  
C. P. Wang ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Effect ◽  
Dielectric Constants ◽  
Batio3 Ceramic ◽  
Grain Size Effect

A basic end-member model algorithm for grain-size data of marine sediments

2020 ◽  
Vol 236 ◽  
pp. 106656 ◽  
Author(s):  
Xiaodong Zhang ◽  
Hongmin Wang ◽  
Shumei Xu ◽  
Zuosheng Yang
Keyword(s):  
Grain Size ◽  
Marine Sediments ◽  
Member Model ◽  
Model Algorithm ◽  
Size Data ◽  
End Member Model
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