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
Clay nanotube-biopolymer composite scaffolds for tissue engineering
02.05.2016 | Kazan Federal University
Personal cooling units on the horizon
29.04.2016 | Penn State
Using an ultra fast-scanning atomic force microscope, a team of researchers from the University of Basel has filmed “living” nuclear pore complexes at work for the first time. Nuclear pores are molecular machines that control the traffic entering or exiting the cell nucleus. In their article published in Nature Nanotechnology, the researchers explain how the passage of unwanted molecules is prevented by rapidly moving molecular “tentacles” inside the pore.
Using high-speed AFM, Roderick Lim, Argovia Professor at the Biozentrum and the Swiss Nanoscience Institute of the University of Basel, has not only directly...
If a person pushes a broken-down car alone, there is a certain effect. If another person helps, the result is the sum of their efforts. If two micro-particles are pushing another microparticle, however, the resulting effect may not necessarily be the sum their efforts. A recent study published in Nature Communications, measured this odd effect that scientists call “many body.”
In the microscopic world, where the modern miniaturized machines at the new frontiers of technology operate, as long as we are in the presence of two...
Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.
Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...
Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.
In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...
Honeycomb structures as the basic building block for industrial applications presented using holo pyramid
Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...
27.04.2016 | Event News
15.04.2016 | Event News
12.04.2016 | Event News
03.05.2016 | Physics and Astronomy
03.05.2016 | Life Sciences
03.05.2016 | Physics and Astronomy