Control, measurement and effects of epitaxial strain in oxides
Control, measurement and effects of epitaxial strain in oxides
Developing faster computer chips and computer memory with greater capacity based on existing technologies is becoming increasingly difficult. New materials are needed to continue innovation in microelectronics. Oxides are an interesting candidate due to their wealth of chemical and physical properties. Ferroics, a group of materials that react strongly to external stimuli such as electric and magnetic fields and mechanical stress, are particularly relevant because they form networks of so-called domain walls that have functionalities concentrated in a very small area. In the future, these domain walls could be used as memory and computing elements in new types of computer chips.
The subject of this thesis is influencing the structure of ferroic materials and the formation process of domain walls in them. This is achieved by applying mechanical strain to the material during its growth, a process known as epitaxy. The resulting mechanical strain in the material, epitaxial strain, is examined from three angles:
- 1. A new method for applying epitaxial strain using a buffer layer is introduced.
- 2. A newly developed software package for measuring epitaxial strain using electron microscopy is described.
- 3. Two examples of the effect of both applying and removing epitaxial strain are shown.
Together, these perspectives provide a new insight into the use of epitaxy for developing new functional materials.