1.中山大学化学学院/生物无机与合成化学教育部重点实验室,广东 广州 510006
2.华东师范大学物理与电子科学学院 / 极化材料与器件教育部重点实验室,上海 200062
宋海利(1989年生),女;研究方向:功能纳米材料微结构;E-mail:songhli@mail.sysu.edu.cn
纸质出版日期:2023-09-25,
网络出版日期:2023-06-30,
收稿日期:2023-05-10,
录用日期:2023-05-23
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宋海利,黄荣.球差校正透射电镜技术探究SrTiO3/SrTiO3 同质薄膜导电起源[J].中山大学学报(自然科学版),2023,62(05):101-106.
SONG Haili,HUANG Rong.Exploring the conductive origin of SrTiO3/ SrTiO3 homogeneous films by spherical aberration-corrected transmission electron microscopy[J].Acta Scientiarum Naturalium Universitatis Sunyatseni,2023,62(05):101-106.
宋海利,黄荣.球差校正透射电镜技术探究SrTiO3/SrTiO3 同质薄膜导电起源[J].中山大学学报(自然科学版),2023,62(05):101-106. DOI: 10.13471/j.cnki.acta.snus.2023B021.
SONG Haili,HUANG Rong.Exploring the conductive origin of SrTiO3/ SrTiO3 homogeneous films by spherical aberration-corrected transmission electron microscopy[J].Acta Scientiarum Naturalium Universitatis Sunyatseni,2023,62(05):101-106. DOI: 10.13471/j.cnki.acta.snus.2023B021.
通过脉冲激光沉积方法沿着SrTiO
3
衬底(001)方向生长了SrTiO
3
/SrTiO
3
(001)同质外延薄膜,薄膜退火前为导电状态,在氧气气氛中退火后变为绝缘态。运用环形高角暗场像、环形明场像和能量损失谱等多种先进的球差校正透射电镜技术,从原子尺度分析薄膜表面和界面处的原子占位、电子结构以及氧空位等。研究发现,退火前薄膜表面存在TiO
x
(
<math id="M1"><mn mathvariant="normal">1</mn><mo><</mo><mi>x</mi><mo><</mo><mn mathvariant="normal">2</mn></math>
https://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=49663310&type=
https://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=49663323&type=
12.36133385
2.28600001
)重构层,退火后重构层仍然存在,但Ti的价态有所升高。同时,通过原子分辨率的能量损失谱分析对比了退火前后Ti和O的价态变化,发现:退火前薄膜表面和界面附近存在氧空位,薄膜表面的氧空位更多,退火后氧空位消失。因此,对于SrTiO
3
/SrTiO
3
同质薄膜来说,薄膜导电的起源主要为薄膜表面和界面附近氧空位的共同作用。
A SrTiO
3
/
SrTiO
3
homogeneous epitaxial film was grown along the SrTiO
3
substrate (001) by PLD method. The film was conductive before annealing, and became insulating states after annealing. A variety of advanced spherical aberration-corrected transmission microscopy techniques like annular high-angle darkfield image, annular brightfield image and atomic-resolution energy loss spectroscope (EELS) was used to explore the atomic occupancy, electronic structure and oxygen vacancies in the film. A TiO
x
<math id="M2"><mo stretchy="false">(</mo><mn mathvariant="normal">1</mn><mo><</mo><mi>x</mi><mo><</mo><mn mathvariant="normal">2</mn><mo stretchy="false">)</mo></math>
https://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=49663314&type=
https://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=49663313&type=
16.93333435
3.47133350
reconstruction layer was found on the surface of the film. And the valence state of Ti in the reconstruction layer increases slightly after annealing. According to EELS analysis, oxygen vacancies existed in the whole film including the surface and interface before annealing, and disappeared after annealing. Therefore, for non-polar films SrTiO
3
/SrTiO
3
, oxygen vacancies near the film surface and interface maybe the origin of electrical conduction.
钙钛矿氧化物球差校正透射电镜电子能量损失谱氧空位
perovskite oxidesspherical aberration-corrected transmission electron microscopeenergy loss spectroscopeoxygen vacancy
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