Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userUnusually strong lateral interaction in the CO overlayer in phosphorene-based systems
49
0
0.0
(
0
)
Added by
Miriam Serena Vitiello Prof
Publication date
2018
fields
Physics
and research's language is
English
Ask ChatGPT about the research
No Arabic abstract
By means of vibrational spectroscopy and density functional theory (DFT), we investigate CO adsorption on phosphorene-based systems. We find stable CO adsorption at room temperature on both phosphorene and bulk black phosphorus. The adsorption energy and vibrational spectrum have been calculated for several possible configurations of the CO overlayer. We find that the vibrational spectrum is characterized by two different C-O stretching energies. The experimental data are in good agreement with the prediction of the DFT model and unveil the unusual C-O vibrational band at 165-180 meV, activated by the lateral interactions in the CO overlayer.
rate research
Read More
Two-dimensional dilute magnetic semiconductors can provide fundamental insights in the very nature of magnetic orders and their manipulation through electron and hole doping. Despite the fundamental physics, due to the large charge density control capability in these materials, they can be extremely important in spintronics applications such as spin valve and spin-based transistors. In this article, we studied a two-dimensional dilute magnetic semiconductors consisting of phosphorene monolayer doped with cobalt atoms in substitutional and interstitial defects. We show that these defects can be stabilized and are electrically active. Furthermore, by including holes or electrons by a potential gate, the exchange interaction and magnetic order can be engineered, and may even induce a ferromagnetic-to-antiferromagnetic phase transition in p-doped phosphorene.
The current-voltage characteristics of thin wires are often observed to be nonlinear, and this behavior has been ascribed to Schottky barriers at the contacts. We present electronic transport measurements on GaN nanorods and demonstrate that the nonlinear behavior originates instead from space-charge-limited current. A theory of space-charge-limited current in thin wires corroborates the experiments, and shows that poor screening in high aspect ratio materials leads to a dramatic enhancement of space-charge limited current, resulting in new scaling in terms of the aspect ratio.
Recent development of the magnetic material engineering led to achievement of the systems with a high interfacial Dzyaloshinskii-Moriya interaction (DMI). As a result, the formation of non-collinear magnetic soliton states or nonreciprocal spin wave dynamics is achievable. Typically used materials are based on bi-layers Heavy Metal/Ferromagnet, e.g., Pt/Co. These layers are characterized not only by a strong DMI, but also by the spin pumping effect and the resulting relatively large damping. Here, we show that the considerable interfacial DMI can be also present in bi-layers based on Ru/Co, characterized with low spin pumping effect and low damping. It is therefore a good candidate for the dynamical studies and implementations of chiral DMI. It is demonstrated by theoretical calculations that the value of DMI can be strongly affected and controlled by the strain of the lattice. We show a systematic experimental and theoretical comparison of magnetic material parameters between Pt/Co and Ru/Co bi-layers as a deserving candidate for spintronic and spin-orbitronic applications.
We investigated the perpendicular exchange bias (PEB) switching from negative- to positive-exchange bias state for Cr2O3/Pt/Co exchange coupling thin film system exhibiting positive exchange bias phenomena. By changing Pt spacer layer thickness or measurements temperature, we demonstrated the control of two kind of intermediate state of the switching; the double hysteresis loop indicating local, non-averaged PEB, and single hysteresis loop indicating averaged PEB. We proposed the way to control the lateral ferromagnetic domain though the control of PEB magnitude.
Despite a decade of research, the precise mechanisms occurring at interfaces underlying the Dzyaloshinskii-Moriya interaction (DMI), and thus the possibility of fine-tuning it, are not yet fully identified. In this study, we investigate the origin of the interfacial DMI, aiming at disentangling how independent are the interfaces around the ferromagnetic layer, and what are their relative contributions to the effective DMI amplitude. For this purpose, we have grown and investigated a large variety of systems with a common structure Pt$|$Co$|M$ with $M =$ Ni, Pd, Ru, Al, Al$|$Ta and MoSi. We explore the correlation between the effective interfacial DMI, and different intrinsic properties of metals, namely atomic number, electronegativity and work function difference at the Co$|M$ interfaces. We find a linear relationship between interfacial DMI and the work function difference between the two elements, hence relating the nature of this behavior to the interfacial potential gradient at the metallic interfaces. The understanding of the DMI mechanism is of utmost importance since it opens up the possibility of precisely engineering the magnetic and hence the spintronic properties for future devices.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
