Researchers at Japan's National Institute for Materials Science (NIMS) and Advanced Institute for Materials Research (AIMR) have achieved the first successful atomic-level observation of growing strontium titanate thin films.
Led by Assistant Professor Takeo Ohsawa of NIMS and Associate Professor Taro Hitosugi of Tohoku University's AIMR, a research team has developed a new advanced system, combining a super-resolution microscope and a deposition chamber for growing oxide thin films.
(Left) Scanning tunneling microscopy image of 0.3 unit-cell SrTiO3 thin film (15 nm × 15 nm). Atomic arrangement is clearly observed to be identical between the SrTiO3 thin film (purple) and the SrTiO3 substrate underneath (blue). (Right) A growth model illustrating the formation of SrTiO3 thin film. The TiO2 layer present on the surface of the SrTiO2 substrate is transferred to the surface of the thin film.
Copyright : National Institute for Materials Science (NIMS)
With this system, they successfully observed for the first time the growing metal-oxide thin films at an atomic level on the surface of single-crystal strontium titanate (SrTiO3). Based on these observations, they identified the mechanism involved in the growth of the thin films in which titanium atoms rose to the surface of the film.
Metal oxides, including perovskite-type oxides such as SrTiO3, are commonly used due to their diverse properties, which include superconductivity, ferromagnetism, ferroelectricity and catalytic effect.
In recent years, novel properties generated at the interface between two dissimilar oxides have been vigorously investigated. However, little is known about the mechanism involved in the formation of such interfaces. Understanding this mechanism is key to further research advances in this field.
The NIMS/AIMR research group developed an innovative system that combines a scanning tunneling microscope capable of identifying individual atoms with a pulsed laser deposition method that enables the growth of high-quality thin films.
In addition, they also established a method for preparing a single-crystal SrTiO3 substrate on which atoms are arranged in a periodic pattern. Epitaxial thin films were grown on the surface of the substrates and the growth was observed with atomic-scale spatial resolution. In their observations, they found there was a great difference in the growth process when SrTiO3 and SrOx thin films were deposited on the surface of the substrates.
Furthermore, the team identified a phenomenon in which excess titanium atoms present on the surface of the SrTiO3 substrate rose to the surface of the thin film. These observations facilitated a clear atomic-scale understanding of the growth process regarding how oxide thin films are formed.
These results may not only contribute to the understanding of the origin of interfacial properties but also lead to the creation of new electronics devices through the development of new functional materials.
This research was carried out as part of the Japan Science and Technology Agency’s Strategic Basic Research Programs. The research will be published in the U.S.-based scientific journal, ACS Nano, in the near future.
Mikiko Tanifuji | Research SEA News
Researchers shoot for success with simulations of laser pulse-material interactions
29.03.2017 | DOE/Oak Ridge National Laboratory
Nanomaterial makes laser light more applicable
28.03.2017 | Christian-Albrechts-Universität zu Kiel
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences