MBE growth and characterization of Co nanostructures on GaAs(001)+20 substrate
مؤلف
Al-Maamariyah, Muna Darwish Abdullah
الملخص الإنجليزي
In this study, cobalt nanostructures were grown epitaixaly on vicinal undoped GaAs (001) + 2° substrates at temperatures in the range from room temperature to 550 C for different deposition times (10 seconds - 15 minutes). The samples were characterized using in-situ techniques such as RHEED (Reflection High Energy Electron Diffraction) and XPS (X-ray Photoemission Spectroscopy). The morphology and the roughness were investigated using ex-situ AFM (Atomic Force Microscopy). The magnetic domains of the cobalt on the surface were studied by ex situ MFM (Magnetic Force Microscopy). It is found that, at room temperature random or Island growth mode occurred. The roughness of the sample grown at 200°C substrate is less than that for the room temperature substrate. The 350°C is the suitable substrate temperature to obtain the layer by layer growth mode of cobalt on GaAs(001) and this sample is more rough than the sample grown at 200°C substrate. The suitable temperature for MBE growth of cobalt at which minimum roughness is satisfied is about (250 = 50)°C.
