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We investigate the magnetization and the Dzyaloshinskii–Moriya interactions (DMI) in Pt/Co/Re thin films in the case of perfect interfaces and upon the introduction of intermixing on both Co interfaces. Calculations were implemented on a series of systems with a countable number of cobalt atomic layers. Remarkably, Re can introduce a DMI at the interface with cobalt and also increase the DMI at the Pt/Co interface. We demonstrate that the chiral magnetic multilayer Pt/Co/Re with a chiral spin structure can achieve a substantial DMI value, which is almost double that attained in the prototype system Pt/Co/W. We also study the DMI as a function of the Re thickness, finding the optimal thickness to maximize the DMI. When we include a disorder that cancels a contribution from all first-neighbor Co atoms in the intermixed region, we find out that intermixing at the two interfaces affects the strength of the DMI solely when introduced at the Pt/Co interface, where the DMI loses almost half of its value. On the contrary, the mixing at the Co/Re interface has very little or no effect where the calculated values were not significantly decreased as compared to the case with perfect interfaces. [ABSTRACT FROM AUTHOR]

We have investigated the early stage of Ag island growth at 2 monolayer (ML) coverage on the hydrogen-terminated Si(111)-(1×1) surface using low-energy electron-diffraction (LEED) and scanning tunneling microscopy (STM) at room temperature. First, it is found that the Ag(10) LEED pattern varies from arc-like spots to three spots by changing the Ag deposition rate from 1:0 × 10-1 (a fast deposition rate) to 1:1 × 10-4 (a slow deposition rate) ML/s. Second, STM observation reveals that adsorbed Ag atoms grow into dome-like three dimensional (3D) clusters at the fast deposition rate and flat-top two dimensional (2D) islands at the slow deposition rate. Third, most abundant 2D islands show the 8 atomic layer height, which coincides with that obtained from the quantum size effect. The side structures of 2D islands agree well with those calculated from Wulff theory. We will discuss the exact nature of 3D clusters and 2D islands of Ag grown on the hydrogen-terminated Si(111)-(1×1) surface and these results indicate the possibility of using kinetic controlled growth to investigate the physics of crystal growth. [ABSTRACT FROM AUTHOR]