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低能Ar+溅射诱导CeO2(111)薄膜还原
发表时间：2012-04-15 浏览量：1591 下载量：491
| 全部作者： | 王国栋，孔丹丹，潘永和，潘海斌，朱俊发 |
| 作者单位： | 中国科学技术大学国家同步辐射实验室 |
| 摘 要： | 利用同步辐射光电子能谱(synchrotron radiation photoemission spectroscopy, SRPES)原位、系统地研究Ar+溅射对在Ru(0001)表面外延生长的CeO2(111)薄膜表面的电子结构和化学成分的影响。结果表明：在1 keV和0.5 μA/cm2的Ar+溅射条件下，Ar+溅射引起费米能级以下1.6 eV处出现Ce3+特征的Ce 4f1峰，归结为CeO2表面的Ce4+被还原成Ce3+. 随着溅射时间的增加，还原态Ce3+的峰强度也逐渐增强。15 min后，当溅射到样品表面的Ar+面密度达到2.8×1015 ions/cm2时，还原态Ce3+的峰强度不再增加，生成Ce3+的数量基本达到饱和。Ar+溅射诱导CeO2表面被还原，是由于样品表面的氧原子被优先刻蚀而引起的。经过15 min的Ar+溅射，样品表面形成了大约0.74 nm的CeO2-x层。得到结论：Ar+溅射是一种使CeO2表面还原成CeO2-x的有效方法，样品表面的还原程度主要取决于溅射Ar+的能量和数量。 |
| 关 键 词： | 物理化学；Ar+溅射；同步辐射；CeO2；优先刻蚀 |
| Title： | Reduction of CeO2(111) film by low energy Ar+ sputtering |
| Author： | WANG Guodong, KONG Dandan, PAN Yonghe, PAN Haibin, ZHU Junfa |
| Organization： | National Synchrotron Radiation Laboratory, University of Science & Technology of China |
| Abstract： | The structure and electronic properties of epitaxial grown CeO2(111) thin films before and after Ar+ bombardment have been systematically studied in situ with synchrotron radiation photoemission spectroscopy (SRPES). Under the condition of the energy of Ar ions being 1 keV and a constant current density of 0.5 μA/cm2, Ar+ bombardment of the surface causes a new emission appearing at 1.6 eV above the Fermi edge, which is related to the localized Ce 4f1 orbital in the reduced oxidation state Ce3+. With increasing time of sputtering, the intensity of the reduced state Ce3+ increases and reaches a constant value after 15 min sputtering, which corresponds to the surface being exposed to 2.8×1015 ions/cm2. The reduction of CeO2 is attributed to a preferential sputtering of oxygen from the surface. Ar+ bombardment leads to a gradual buildup of an, approximately 0.74 nm thick, sputtering altered layer after 15 min sputtering. These studies have demonstrated that Ar+ bombardment is an effective method for reducing CeO2 to CeO2-x and the degree of the reduction is related to the energy and amount of Ar ions been exposed to the CeO2 surface. |
| Key words： | physical chemistry; Ar+ sputtering; synchrotron radiation; cerium oxide; preferential sputtering |
| 发表期数： | 2012年4月第7期 |
| 引用格式： | 王国栋，孔丹丹，潘永和，等. 低能Ar+溅射诱导CeO2(111)薄膜还原[J]. 中国科技论文在线精品论文，2012，5（7）：607-614. |
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