Interfacial Structure of Ti2AlN Thin Films on MgO(111)

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• 作者：Hongmei Jin ; Zheng Zhang ; Yanguang Nie ; Yingzhi Zeng ; Lu Shen ; Michael B. Sullivan ; Shi Jie Wang
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：August 15, 2013
• 年：2013
• 卷：117
• 期：32
• 页码：16515-16522
• 全文大小：429K
• 年卷期：v.117,no.32(August 15, 2013)
• ISSN：1932-7455

文摘

Single-crystalline Ti₂AlN thin films have been grown on MgO(111) substrates at 750 掳C using DC magnetron sputtering from a Ti₂Al alloy target in a mixed N₂/Ar plasma. X-ray diffraction and transmission electron microscopy confirm epitaxial layered growth of Ti₂AlN (0001) on MgO(111). On the basis of the experimental results, ab initio calculations were carried out to study the geometry and electronic structure between Ti₂AlN and oxygen/magnesium -terminated MgO polar surfaces. A total of eight interface structures were calculated, and results showed that the adhesion between Ti₂AlN (0001) and O-terminated MgO(111) is stronger than that with Mg-terminated MgO(111) surfaces in general. In particular, the largest adhesion energy was found for the interfacial structure with N鈥揟i鈥揂l鈥揟i/O鈥揗g configuration. The stronger adhesion is due to reactive nature of Ti₂AlN surface with N鈥揟i鈥揂l鈥揟i stacking sequence. In addition, electronic structure calculation results showed that there is charge transferring between Ti₂AlN and MgO with directions from Ti₂AlN to MgO for O termination and from MgO to Ti₂AlN for Mg termination. Moreover, the adhesion energies and charge-transferring amount are independent of the layer thickness of Ti₂AlN, indicating that the interaction between Ti₂AlN and MgO is rather localized.