Structural and compositional characteristics of MgO-based magnetic tunnel junctions were characterized using advanced transmission electron and focused-ion beam microscopies. These junctions were fabricated from two ferromagnetic layers separated by a dielectric one and have a switchable resistance that depends upon the relative magnetizations of those two ferromagnetic layers. Certain etching conditions were used to complete the fabrication process aiming to achieve sharp-edge profiles on either side of the pillars. Controlling the edge profiles of those fabricated pillars enables to avoid shortcuts that induce magnetoresistance effect. Not only structural properties of each layer in the MgO junction are characterized, but its compositional characteristics are also explored with electron energy loss spectroscopy, this aims to elucidate the role of elements existing in the given MgO structure. Results of this work are of technological interest since they provide a better understanding in the microstructural properties of the MgO-based magnetic tunnel junctions.

Most hBN nanostructures were fabricated using the chemical method. However, growing by the physical method also has many advantages, they are easy to synthesize this material on a large area with up-scaling setups. Even two-dimensional hexagonal boron nitride is similar to graphene structure, however there is a little work referring to the fabrication process of this material. Hence, a sufficiently detailed report on physically fabricated hBN materials is essential. This review analyzes the results that we have studied over the past ten years with the synthesis and fabrication of this material using physical vapor deposition – RF sputtering, incorporation with other techniques, strongly emphasized on growth mechanisms of this material.