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
Custom sequences for polymers using visible light
22.03.2018 | Tokyo Metropolitan University
The search for dark matter widens
21.03.2018 | American Institute of Physics
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
22.03.2018 | Trade Fair News
22.03.2018 | Earth Sciences
22.03.2018 | Earth Sciences