| PbTiO3多晶及薄膜材料强电场下的电热效应研究 |
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| 引用本文： | 陈迎杰,封文江,郝爽.PbTiO3多晶及薄膜材料强电场下的电热效应研究[J].沈阳师范大学学报(自然科学版),2011,29(2):189-193. |
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| 作者姓名： | 陈迎杰 封文江 郝爽 |
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| 作者单位： | 沈阳师范大学,物理科学与技术学院,沈阳,100034 |
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| 基金项目： | 辽宁省科技厅科学技术计划项目，沈阳师范大学实验中心主任基金重点项目 |
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| 摘 要： | 基于Landau-Devonshire的热动力学模型,计算了PbTiO3块体及薄膜材料在铁电相变附近的电热效应。PbTiO3块体在769 K出现了一级铁电-顺电转变。700 K时其矫顽场为25MV·m-1。强的电场使得PbTiO3块体材料的一级相变逐渐转变为二级连续相变,且相变在更高的温度发生。PbTiO3薄膜材料的相变为二级相变,熵值减小,而熵变也相应减少。随着电场的增强,两者的比热容减小,但对应的温度向高温方向移动,2者的熵值却随着电场的增大而增强。对于PbTiO3薄膜来说,随着面内错配度的变化,张应力使相变温度降低,而压应力则相反。计算了PbTiO3块体与薄膜材料的绝热温变与制冷热容,其中块体的绝热温变ΔTad与制冷热容RC最大,分别为4.76 K与94.1 kJm-2K-1。
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| 关 键 词： | 电热效应 铁电相变 铁电薄膜 |
Electrocaloric effect in PbTiO3 thin films in high electric field |
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| CHEN Ying-jie,FENG Wen-jiang,HAO Shuang.Electrocaloric effect in PbTiO3 thin films in high electric field[J].Journal of Shenyang Normal University: Nat Sci Ed,2011,29(2):189-193. |
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| Authors: | CHEN Ying-jie FENG Wen-jiang HAO Shuang |
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| Institution: | CHEN Ying-jie,FENG Wen-jiang,HAO Shuang(College of Physics Science and Technology,Shenyang Normal University,Shenyang 110034,China) |
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| Abstract: | Based on Landau-Devonshire theory,the electrothermal properties of PbTiO3 bulk and film are computed near the temperatures of their first-order phase transitions.A first-order ferroelectric to paraelectric phase transition is present in PbTiO3 bulk.At 700 K,the coercive electric field is about 25 MVm-1.High applied electric fields drive the transition to higher temperatures and the P-T curves to be continuous.For PbTiO3 film,the second-order phase transition reduces the excess entropy,and thereby the isothe... |
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| Keywords: | electrocaloric effect ferroelectric phase transition ferroelectric thin film |
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