无机材料学报

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Gd掺杂对PZT薄膜介电性能及极化行为的影响

孙秋1,2, 魏兆冬2, 王福平2, 姜兆华2   

  1. 哈尔滨工业大学1. 化学工程与技术博士后流动站, 2. 应用化学系, 哈尔滨 150001
  • 收稿日期:2007-10-15 修回日期:2007-12-20 出版日期:2008-09-20 网络出版日期:2008-09-20

Effect of Gd Doping on Dielectric Properties and Polarization Behavior of Lead Zirconate Titanate Thin Films

SUN Qiu1,2, WEI Zhao-Dong2, WANG Fu-Ping2, JIANG Zhao-Hua2   

  1. 1. Postdoctoral Station of Chemistry Engineering and Technology, Harbin Institute of Technology, Harbin 150001, China; 2. Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001, China
  • Received:2007-10-15 Revised:2007-12-20 Published:2008-09-20 Online:2008-09-20

摘要: 采用sol-gel法在Pt/Ti/SiO2/Si衬底上制备出高度(100)择优取向的Gd掺杂PZT薄膜(简写为PGZT); 介电测试结果表明, 1mol%Gd掺杂的PZT薄膜介电常数最大, 2mol%Gd掺杂PZT薄膜与未掺杂薄膜的介电常数相差不大, Gd掺入量>2mol%时, 薄膜的介电常数下降; 薄膜的不可逆极化值呈现与介电常数相同的变化趋势, 而可逆极化值变化较小. 在弱电场下(低于矫顽场Ec), 用瑞利定律分析薄膜介电常数随电场强度的变化规律, 1mol%Gd掺杂的薄膜瑞利系数α最大, 说明薄膜中缺陷的浓度最低. 1mol%Gd掺杂的薄膜介电和铁电性能的改善与Gd3+在PZT晶格中的占位情况有关.

关键词: PZT薄膜, 稀土掺杂, 介电性能, 极化行为

Abstract: Highly (100)-oriented Pb(Zr0.52Ti0.48)O3 thin films with different Gd dopants (PGZTx, x=0, 1mol%, 2mol%, 3mol%, 5mol% Gd) were prepared on Pt/Ti/SiO2/Si substrates by the sol-gel technique and rapid thermal annealing (RTA) process. The dielectric properties of the PZT thin films with 1mol% Gd dopant is improved with increased dielectric permittivity and decreased dielectric dissipation. However, when Gd dopants are more than 2mol%, dielectric properties of the doped PZT thin films are deteriorated obviously including decrease of dielectric permittivity, increase of dielectric dissipation. At the saturation field, the irreversible polarization first increases when Gd content is 1mol% and then decreases when Gd contents are more than 2mol%, the reversible polarization remains almost constant in all PGZT thin films. The so-called Rayleigh law used to describe the hysteresis of ferromagnetic materials in the subcoercive regime can be extended to describe the subcoercive hysteresis in ferroelectric PGZT materials. The mechanism of the Gd dopant effect on the dielectric properties and polarization behavior is also discussed.

Key words: PZT thin films, rare-earth doping, dielectric properties, polarization

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