At heterointerfaces between complex oxides with polar discontinuity, the instability-induced elec... more At heterointerfaces between complex oxides with polar discontinuity, the instability-induced electric field may drive electron redistribution, causing a dramatic change in the interfacial charge density. This results in the emergence of a rich diversity of exotic physical phenomena in these quasi-two-dimensional systems, which can be further tuned by an external field. To develop novel multifunctional electronic devices, it is essential to control the growth of polar oxide films and heterointerfaces with atomic precision. In this article, we review recent progress in control techniques for oxide film growth by molecular beam epitaxy (MBE). We emphasize the importance of tuning the microscopic surface structures of polar films for developing precise growth control techniques. Taking the polar SrTiO 3 (110) and (111) surfaces as examples, we show that, by keeping the surface reconstructed throughout MBE growth, high-quality layer-by-layer homoepitaxy can be realized. Because the stability of different reconstructions is determined by the surface cation concentration, the growth rate from the Sr/Ti evaporation source can be monitored in real time. A precise, automated control method is established by which insulating homoepitaxial SrTiO 3 (110) and (111) films can be obtained on doped metallic substrates. The films show atomically well-defined surfaces and high dielectric performance, which allows the surface carrier concentration to be tuned in the range of ∼10 13 /cm 2. By applying the knowledge of microstructures from fundamental surface physics to film growth techniques, new opportunities are provided for material science and related research.
for their guidance and support throughout the course of this research. In addition, I would also ... more for their guidance and support throughout the course of this research. In addition, I would also like to thank my parents, my wife, my friends and my siblings for their unfailing support during my studies, and my colleagues, the department faculty and staff for making my time at Iowa State University a wonderful experience. I want to also offer my appreciation to those who were willing to participate in my research, without whom, this thesis would not have been possible. Finally, I would like to express my gratitude to the Government of Saudi Arabia for sponsoring me to conduct my studies in the United States.
At heterointerfaces between complex oxides with polar discontinuity, the instability-induced elec... more At heterointerfaces between complex oxides with polar discontinuity, the instability-induced electric field may drive electron redistribution, causing a dramatic change in the interfacial charge density. This results in the emergence of a rich diversity of exotic physical phenomena in these quasi-two-dimensional systems, which can be further tuned by an external field. To develop novel multifunctional electronic devices, it is essential to control the growth of polar oxide films and heterointerfaces with atomic precision. In this article, we review recent progress in control techniques for oxide film growth by molecular beam epitaxy (MBE). We emphasize the importance of tuning the microscopic surface structures of polar films for developing precise growth control techniques. Taking the polar SrTiO 3 (110) and (111) surfaces as examples, we show that, by keeping the surface reconstructed throughout MBE growth, high-quality layer-by-layer homoepitaxy can be realized. Because the stability of different reconstructions is determined by the surface cation concentration, the growth rate from the Sr/Ti evaporation source can be monitored in real time. A precise, automated control method is established by which insulating homoepitaxial SrTiO 3 (110) and (111) films can be obtained on doped metallic substrates. The films show atomically well-defined surfaces and high dielectric performance, which allows the surface carrier concentration to be tuned in the range of ∼10 13 /cm 2. By applying the knowledge of microstructures from fundamental surface physics to film growth techniques, new opportunities are provided for material science and related research.
for their guidance and support throughout the course of this research. In addition, I would also ... more for their guidance and support throughout the course of this research. In addition, I would also like to thank my parents, my wife, my friends and my siblings for their unfailing support during my studies, and my colleagues, the department faculty and staff for making my time at Iowa State University a wonderful experience. I want to also offer my appreciation to those who were willing to participate in my research, without whom, this thesis would not have been possible. Finally, I would like to express my gratitude to the Government of Saudi Arabia for sponsoring me to conduct my studies in the United States.
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Papers by Muath Khawaji