Growth morphology of Pb films on Ni₃Al(111)

详细信息    查看全文

• 作者：K. Mi艣k贸w ; A. Krupski ; K. W ; elt
• 关键词：Lead ; Nickel ; Aluminium ; Alumina ; Crystal growth ; Thin film growth ; Metal&ndash ; metal interfaces ; Low-index single crystal surface ; Crystalline structure ; Auger electron spectroscopy (AES) ; Scanning tunnelling microscopy (STM)
• 刊名：Vacuum
• 出版年：March, 2014
• 年：2014
• 卷：101
• 期：Complete
• 页码：71-78
• 全文大小：1815 K

文摘

Scanning tunnelling microscopy (STM) and Auger electron spectroscopy (AES) have been used to investigate the growth morphology of ultra-thin Pb films on the Ni₃Al(111) face at room temperature. A聽previous study [K. Mi艣k贸w and A. Krupski Appl Surf Sci 273, 2013, 554] using low-energy electron diffraction (LEED) and real time Auger intensity recording has demonstrated that an initial two-dimensional growth of the first Pb monolayer thick 鈥?em>wetting layer鈥?takes place. With further deposition and for T聽=聽300聽K, flat three atomic-layer-high islands are grown. Above 350聽K, the Stranski-Krastanov growth mode was observed. In the current study, the analysis of STM measurements indicate and confirm that for coverage 胃聽=聽1.0聽ML two-dimensional growth of the first Pb monolayer took place. Above 胃聽>聽1.0聽ML, a three-dimensional growth of the Pb islands was observed with a strongly preferred atomic-scale 鈥?em>magic height (N),鈥?hexagonal shape and flat-tops. At coverage 胃聽=聽3.5聽ML, only islands containing N聽=聽3, 5, 7 and 11 atomic layers of Pb are observed. At the higher coverage 胃聽=聽5.5聽ML, three types of regular hexagonal islands with side lengths of 25, 30 and 45聽nm are observed. Furthermore, three different island adsorption configurations rotated by 10掳聽卤聽1掳 and 30掳聽卤聽6掳 with respect to each other were observed. After an annealing at T聽=聽400聽K of 5.5聽ML of lead deposited at RT on the Ni₃Al(111) the morphology of the surface changes. Post-anneal, islands of Pb are observed above the 鈥?em>wetting layer鈥?with an estimated average size and diameter of 768聽卤聽291聽nm² and 38.17聽卤聽6.56聽nm and constant uniform height of two atomic layers (N聽=聽2).