Article
Chemistry, Physical
Yuting Shen, Hailin Yu, Tao Xu, Qiubo Zhang, Kuibo Yin, Shan Cong, Yushen Liu, Litao Sun
Summary: Two types of edge structures, semiconducting flat edges and metallic zigzag edges, are found in single-layer Bi2Te3, and the proportions of these edges can be controlled by electron beam irradiation.
Article
Chemistry, Analytical
Vyacheslav V. Marchenkov, Alexey V. Lukoyanov, Semyon T. Baidak, Alexandra N. Perevalova, Bogdan M. Fominykh, Sergey V. Naumov, Elena B. Marchenkova
Summary: This study investigates the electrical resistivity and the Hall effect of topological insulator Bi2Te3 and Bi2Se3 single crystals. The results show a clear correlation between the density of electronic states at the Fermi level and the current carrier concentration. With increasing temperature, the density of states and the carrier concentration increase for Bi2Te3, while they decrease for Bi2Se3.
Article
Nanoscience & Nanotechnology
Yongchen Liu, Wilder Acuna, Huairuo Zhang, Dai Q. Ho, Ruiqi Hu, Zhengtianye Wang, Anderson Janotti, Garnett Bryant, Albert V. Davydov, Joshua M. O. Zide, Stephanie Law
Summary: Terahertz technologies have broad applications and researchers are exploring the growth of Bi2Se3 on GaAs substrates as a step towards on-chip THz integrated systems. The study finds that achieving high-quality Bi2Se3 films requires an atomically smooth GaAs surface.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Ondrej Dyck, Andrew R. Lupini, Stephen Jesse
Summary: The scanning transmission electron microscope is being developed into a platform for atomic-scale material manipulation and fabrication, offering new capabilities and applications. This approach may significantly impact research in microelectronics, quantum information science, and catalysis, by enabling precise control over atomic-scale structure and chemistry, and providing a better understanding of atomic-scale processes for larger-scale synthesis.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Nikhila C. Paranamana, Ryan Gettler, Henry Koenig, Stephen Montgomery-Smith, Xiaoqing He, Matthias J. Young
Summary: Understanding the atomic structure of ultrathin ALD coatings is crucial for establishing structure-property relationships and stabilizing battery interfaces. This study used cryogenic scanning transmission electron microscopy to directly measure atomic structural variations across the depth of an ALD AlOx film deposited onto a carbon nanotube substrate. The results confirmed a proposed two-phase bulk/interface structural model and revealed a thicker interfacial layer than previously reported.
ACS APPLIED NANO MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Puspendu Guha, Joon Young Park, Janghyun Jo, Yunyeong Chang, Hyeonhu Bae, Rajendra Kumar Saroj, Hoonkyung Lee, Miyoung Kim, Gyu-Chul Yi
Summary: We report on the heteroepitaxial growth of Sb2Te3-Bi2Te3 lateral heterostructures using molecular beam epitaxy. The lateral heterostructures were fabricated by growing Bi2Te3 islands on graphene substrates and laterally growing Sb2Te3 on the side facets of the nanostructures. Electron microscopy techniques and first-principles calculations were used to study the interface and topological properties of the heterostructures.
Article
Engineering, Electrical & Electronic
A. M. Adam, A. K. Diab, Mohamed Tolan, Z. M. H. El-Qahtani, A. A. Refaat, Medhat A. El-Hadek, E. M. Elsehly, A. El-Khouly, Abdulaziz N. Alharbi, V Khovaylo, M. Ataalla
Summary: Thin layers of (Bi2Se3)(1-x)(Bi2Te3)(x) samples were prepared by vacuum thermal evaporation technique. The structure properties and optical properties of the synthesized films were characterized and discussed. The films exhibited growing transparency and varying optical band gap energy beyond the visible light region, and the incorporation of Bi2Te3 enhanced the light transmission in layered bismuth chalcogenides.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Ondrej Dyck, Sinchul Yeom, Andrew R. Lupini, Jacob L. Swett, Dale Hensley, Mina Yoon, Stephen Jesse
Summary: Atomic-scale engineering combines bottom-up and top-down approaches to achieve atomic-scale precision patterning in twisted bilayer graphene, using an aberration-corrected scanning transmission electron microscope (STEM) and controlled ejection of carbon atoms. The application of global and local parameters allows for spontaneous arrangement of atoms and migration of adatoms on the material surface. Image-based feedback control facilitates the attachment of arbitrary patterns of atoms and atom clusters with limited human intervention. The role of substrate temperature in adatom and vacancy diffusion is studied through simulations.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Sumit Bera, P. Behera, R. Venkatesh, Uday Deshpande, P. Garg, V Ganesan
Summary: The magnetotransport and thermoelectric properties of Bi2-xCoxTe3 nanomaterials are influenced by the incorporation of cobalt, resulting in a significant change in the electrical resistivity behavior, possibly due to electron-electron interaction and quantum interference effect.
Article
Physics, Condensed Matter
Klaus Zollner, Jaroslav Fabian
Summary: Prototypical 3D topological insulators of the Bi2Se3 family demonstrate the appearance of surface states within the bulk bandgap due to spin-orbit coupling-induced topology. On the other hand, graphene placed on the surface of a topological insulator shows interesting electronic properties of its Dirac electrons, induced by giant spin-orbit coupling through the proximity effect.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2021)
Article
Chemistry, Physical
Ondrej Dyck, Andrew R. Lupini, Stephen Jesse
Summary: The engineering of quantum materials involves the development of tools for synthesis and characterization challenges. One key factor is atomic-scale modification for desired atomic structures. The use of scanning transmission electron microscopes (STEMs) allows for atomic-scale material manipulation but obstacles like in situ material delivery exist. This article presents progress on in situ thermal deposition platform for synthesis processes in a scanning transmission electron microscope.
Article
Physics, Applied
Sumit Bera, Prakash Behera, R. Venkatesh, V. Ganesan
Summary: The magnetotransport and thermal properties of microwave-synthesized nanostructured Bi2Te3 were studied in detail, revealing a disorderly metal-like behavior at high temperatures and a tendency towards localization at low temperatures. The normalized conductivity showed sharp changes in slopes with magnetic fields, indicating dominance of electron-electron interaction and quantum interference effect in transport. Additionally, a transition from positive to negative Coulomb screening factor in Bi2Te3 was observed.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Sigurd Wenner, Adrian Lervik, Elisabeth Thronsen, Calin D. Marioara, Stephan Kubowicz, Randi Holmestad
Summary: Electropolishing is a common method for preparing samples of aluminium alloys for electron microscopy, but it can create a Cu-rich layer between the aluminium matrix and outermost aluminium oxide layer, affecting electron images and diffraction patterns. Care should be taken to account for this potential interference.
MATERIALS CHARACTERIZATION
(2021)
Article
Chemistry, Multidisciplinary
Ondrej Dyck, Andrew R. Lupini, Stephen Jesse
Summary: In this study, we demonstrate an electron beam direct-write process in an aberration-corrected scanning transmission electron microscope. This process differs from conventional electron-beam-induced deposition techniques as it uses a different mechanism and elemental tin (Sn) as a precursor to enable atom-by-atom direct writing. The atomic-sized electron beam is used to generate chemically reactive point defects in a graphene substrate, allowing the precursor atoms to migrate and bond to the defect sites for deposition.
Article
Nanoscience & Nanotechnology
D. V. Louzguine-Luzgin, E. N. Zanaeva, F. R. Pratama, T. Wada, S. Ito
Summary: The structural features of Pd42.5Cu30Ni7.5P20 and Pt42.5Cu27Ni9.5P21 metallic glasses were examined using high-resolution transmission electron microscopy. Pd42.5Cu30Ni7.5P20 exhibited true bulk glass-forming behavior without crystalline particles/nuclei, while Pt42.5Cu27Ni9.5P21 was a crystal growth-controlled bulk glass-former containing nanoparticles with a different chemical composition and an average size of about 1 nm. These structural differences influenced the mechanical properties at room temperature. Thermodynamic calculations supported the observed features.
SCRIPTA MATERIALIA
(2023)
