MBE Molecular beam epitaxy (MBE) is a set of ultrahigh vacuum (UHV) techniques developed since the late 1970s. This breakthrough makes it possible highly controlled coherent epitaxial growth under non-equilibrium conditions. MBE operates in a UHV environment, typically <10-10 torr. By heating and evaporating highly purified elemental sources, i.e. atomic beams, atomic layers can be deposited on the substrate one-at-a-time, and they can be forced to adhere to the same lattice structure of the substrate, i.e. epitaxy. Therefore, by choosing a particular substrate and a set of growth parameters, one can produce non-equilibrium crystalline structures, which in turn makes it possible to tailor and examine materials and properties on atomic scale. The use of combinatorial approach to vary some of the parameters on a single substrate can dramatically enhance the speed to probe the large parameter space and the ability to resolve abrupt transitions. The essence of a controlled combinatorial MBE is the ability to place a tailored set of materials parameters, the “variables”, such as composition, film thickness, and epitaxial strain, onto a single substrate and to examine the corresponding properties systematically. Each combinatorial sample could have one, or two variables “programmed” onto it, effectively slicing through the parameter space and thus enabling investigation of the corresponding behaviors systematically. For example, by moving sample masks, in front of the sample, at a constant speed and constant flux, one can deposit a linear composition profile (a wedge) on the substrate. This way, one can “program” one variable onto the sample. The steps can be repeated to deposit multiple composition profiles with a number of elements. Specs Source: Four electron beam hearths and four effusion cells with total twelve materials. Sample manipulator: 6-axis freedom, temperature control from -100C to 1500C. Mask: two step motor controlled masks Flux monitor: Quartz Crystal monitor Residual gas analyzer Atomic Absorption spectrometer (less 1s responding time)