| 1. |
- Samantara, Aneeya K., et al.
(författare)
-
Enhanced Oxygen Evolution Reaction with a Ternary Hybrid of Patronite-Carbon Nanotube-Reduced Graphene Oxide : A Synergy between Experiments and Theory
- 2021
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:30, s. 35828-35836
-
Tidskriftsartikel (refereegranskat)abstract
- This work reports the hybridization of patronite (VS4) sheets with reduced graphene oxide and functionalized carbon nanotubes (RGO/FCNT/VS4) through a hydrothermal method. The synergistic effect divulged by the individual components, i.e., RGO, FCNT, and VS4, significantly improves the efficiency of the ternary (RGO/FCNT/VS4) hybrid toward the oxygen evolution reaction (OER). The ternary composite exhibits an impressive electrocatalytic OER performance in 1 M KOH and requires only 230 mV overpotential to reach the state-of-the-art current density (10 mA cm–2). Additionally, the hybrid shows an appreciable Tafel slope with a higher Faradaic efficiency (97.55 ± 2.3%) at an overpotential of 230 mV. Further, these experimental findings are corroborated by the state-of-the-art density functional theory by presenting adsorption configurations, the density of states, and the overpotential of these hybrid structures. Interestingly, the theoretical overpotential follows the qualitative trend RGO/FCNT/VS4 < FCNT/VS4 < RGO/VS4, supporting the experimental findings.
|
|
| 2. |
- Goyat, E., et al.
(författare)
-
Large exchange bias and spin pumping in ultrathin IrMn/Co system for spintronic device applications
- 2022
-
Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332. ; 588
-
Tidskriftsartikel (refereegranskat)abstract
- Few nanometers thick antiferromagnetic/Ferromagnetic bilayer based spintronic devices have emerged as a potential nanostructured bilayer for achieving ultrahigh-speed magnetization switching, low power dissipation, terahertz magnetization dynamics, and are compatible with CMOS technology. The systematic investigation of the exchange bias (EB) in theIr(22)Mn(78)/Co system is performed by varying Co thickness (t(Co)) in the range of 6-20 nm with 10 nm thin Ir22Mn78 layer on top, using longitudinal magneto-optic Kerr effect (L-MOKE) and ferromagnetic resonance (FMR) measurements at room temperature. Here, we report the occurrence of a record high EB field in this bilayer system, which is 13.11 mT (9.04 mT) statically (dynamically) for 6 nm thick of Co. The percentage change of 313.5 % (251.7%) in exchange bias field is found through FMR (MOKE) measurements with respect to t(Co) variation from 20 to 6 nm. Additionally, the spin pumping mechanism is also studied in the above stated material system by using the FMR technique. The observed linear dependence of effective Gilbert's damping with respect to the 1/t(Co)& nbsp;, indicates the occurrence of spin pumping phenomena. The study suggests that tunability of both the exchange interaction and spin pumping behavior in this Ir22Mn78/Co system, makes this system suitable for future antiferromagnetic spintronic devices.
|
|
| 3. |
- Husain, S., et al.
(författare)
-
Large Dzyaloshinskii-Moriya interaction and atomic layer thickness dependence in a ferromagnet- WS2 heterostructure
- 2022
-
Ingår i: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 105:6
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional transition metal dichalcogenides (TMDs) have immense potential for spintronics applications. Here, we report atomic layer thickness dependence in WS2/Co3FeB heterostructures. The layer dependence is predicted by density functional theory and demonstrated experimentally by the layer dependence of the Dzyaloshinskii-Moriya interaction (DMI). Notably, we have observed the DMI in WS2 to be larger than that for heavy metals such as W and Ta, which is important to stabilize chiral structures. Inversion symmetry is not preserved with an odd number of layers, while it exists with an even number of layers. This symmetry rule is reflected in the temperature dependence of the effective damping parameter of the heterostructure. That the damping parameter decreases (increases) in odd (even) layers can be resolved at low temperature. This suggests that the layer dependence has its origin at the WS2 interface, where the spin-valley coupling and spin-orbit coupling activate these features. Large DMI, pure spin current, and unique layer dependence in TMDs provide valuable information and fundamental understanding for designing TMD-based quantum information storage devices. © 2022 American Physical Society.
|
|
| 4. |
- Hait, S., et al.
(författare)
-
Impact of ferromagnetic layer thickness on the spin pumping in Co60Fe20B20/Ta bilayer thin films
- 2021
-
Ingår i: Journal of Materials Science-Materials in Electronics. - : Springer Science and Business Media LLC. - 0957-4522 .- 1573-482X. ; 32, s. 12453-12465
-
Tidskriftsartikel (refereegranskat)abstract
- We report the tuneable spin angular momentum transfer (spin pumping) from Co60Fe20B20 (CFB) amorphous alloy into the Ta heavy metal nanolayers. All the films are grown on Si (100) substrate at room temperature using ion-beam sputtering technique. Structural studies reveal that the grown Ta films over amorphous CFB are crystalline even at ultrathin regime. The bilayers possess very low interface roughness (< 0.5 nm) and are continuous throughout the thickness range. Comparative analysis of the spin pumping in CFB (4, 6 and 8 nm) as a function of the Ta thickness (vary from 1 to 10 nm in step of 1 nm) has been performed employing ferromagnetic resonance (FMR) spectroscopy. It is observed that the effective damping increase exponentially with the increase of Ta, (i.e. follows ballistic spin transport) in two series of CFB (4 nm)/Ta (0-10 nm) and CFB(6 nm)/Ta (0-10 nm) bilayers, which is characteristic of normal spin pumping. However, the anomalous behaviour has been observed for CFB (8 nm)/Ta (0-10 nm) bilayer series where the spin current generated in Ta with the thicker CFB behaves oppositely. The results demonstrate the strong dependence of ferromagnet thickness on the spin pumping into the Ta nanolayers. This study paves the way to choose suitable ferromagnetic layer thickness for spin current-induced switching applications in spintronics.
|
|
