张应力对准同形相界Pb(Zr,Ti)O_3薄膜相变和铁电性能影响  

Influence of tensile stress on the phase formation and electronic properties of Pb(Zr,Ti) O_3 film at morphotropic phase boundary

作　　者：闻心怡[1] 王耘波[1] 周文利[1] 高俊雄[1] 于军[1] 

机构地区：[1]华中科技大学电子科学与技术系,武汉430074

出　　处：《物理学报》2011年第9期641-649,共9页Acta Physica Sinica

基　　金：国家自然科学基金重大研究计划(批准号:90407023);国家自然科学基金面上项目(批准号:60971008)资助的课题~~

摘　　要：采用射频磁控溅射法在Pt/TiOx/SiO2/Si基片上制备了以BaPbO3(BPO)为缓冲层的Pb(Zr0.52,Ti0.48)Nb0.04O3(Nb掺杂PZT,PZTN)薄膜.通过调整BPO层厚度,为该PZTN薄膜引入了不同的张应力.当BPO层厚度分别为68nm和135nm时,PZTN薄膜呈现随机取向,采用2θ-sin2ψ法测得薄膜的张应力为0.786和0.92GPa.电学测试表明,张应力较大的PZTN薄膜具有更好的铁电和漏电流性能.当PZTN薄膜张应力为0.786GPa时,剩余极化Pr和矫顽场Ec分别为41.2μC/cm2和70.7kV/cm,在+5V下漏电流密度分别为6.57×10-7A/cm-2;而当张应力增为0.92GPa时,剩余极化Pr增为44.1μC/cm2,矫顽场Ec减为58.1kV/cm,+5V下漏电流密度为5.54×10-8A/cm-2.以掠射方式对两种PZTN薄膜做精细扫描,并结合结构精修进一步分析,分析表明张应力较大的PZTN薄膜中单斜相成份较多,这可能是其铁电性能更加优异的原因.Pb（Zr0.52,Ti0.48）Nb0.04O3 （Nb-doped PZT, PZTN） films are deposited on Pt/TiOx/SiO2/Si substrates with BaPbO3（BPO） buffer layers by RF-magnetron sputtering method. The magnitudes of tensile stress in PZTN films can be changed by adjusting the thickness of BPO layer. For PZTN films with 68 nm and 135 nm-BPOs, the tensile stresses measured by 2θ-sin2ψ method are 0.786 and 0.92 GPa respectively. Enhanced ferroelectric is observed in PZTN film with raised tensile stress. The remanent polarization and the coercive field for PZTN films with tensile stresses of 0.786 GPa and 0.92 GPa are 41.2μC/cm2（70.7 kV/cm） and 44.1μC/cm2（58.1 kV/cm） respectively. The leakage current decreases from 6.57×10-7A/cm-2 to 5.54×10-8A/cm-2 while tensile stress of PZTN film is raised from 0.786 to 0.92GPa. Fine XRD scan is performed with grazing incidence geometry to investigate the phase composition of PZTN films. Rietveld analysis shows that an increased tensile stress in PZTN film can promote the amount of monoclinic phase,which may be the reason for the ferroelectric property improvement.

关 键 词：PZT 准同形相界 掠射扫描方式 结构精修 

分 类 号：O484.4[理学—固体物理]