Author Affiliations
Abstract
1 Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849, United States of America
2 Department of Mechanical and Material Engineering, Auburn University, Auburn, AL 36849, United States of America
Recently, there has been substantial interest in the large-scale synthesis of hierarchically architectured transition metal dichalcogenides and designing electrodes for energy conversion and storage applications such as electrocatalysis, rechargeable batteries, and supercapacitors. Here we report a novel hybrid laser-assisted micro/nanopatterning and sulfurization method for rapid manufacturing of hierarchically architectured molybdenum disulfide (MoS2) layers directly on molybdenum sheets. This laser surface structuring not only provides the ability to design specific micro/nanostructured patterns but also significantly enhances the crystal growth kinetics. Micro and nanoscale characterization methods are employed to study the morphological, structural, and atomistic characteristics of the formed crystals at various laser processing and crystal growth conditions. To compare the performance characteristics of the laser-structured and unstructured samples, Li-ion battery cells are fabricated and their energy storage capacity is measured. The hierarchically architectured MoS2 crystals show higher performance with specific capacities of about 10 mAh cm-2, at a current rate of 0.1 mA cm-2. This rapid laser patterning and growth of 2D materials directly on conductive sheets may enable the future large-scale and roll-to-roll manufacturing of energy and sensing devices.
2D materials laser manufacturing laser patterning energy applications Li-ion battery International Journal of Extreme Manufacturing
2022, 4(4): 045102
Author Affiliations
Abstract
1 Department of Physics, University of Konstanz, 78457 Konstanz, Germany
2 Institute for Physics of Microstructures of RAS, 603950 GSP-105 Nizhny Novgorod, Russian
Current magnetic memories are based on writing and reading out the domains with opposite orientation of the magnetization vector. Alternatively, information can be encoded in regions with a different value of the saturation magnetization. The latter approach can be realized in principle with chemical order-disorder transitions in intermetallic alloys. Here, we study such transformations in a thin-film (35 nm) Fe60Al40alloy and demonstrate the formation of periodic magnetic nanostructures (PMNS) on its surface by direct laser interference patterning (DLIP). These PMNS are nonvolatile and detectable by magnetic force microscopy (MFM) at room temperature after DLIP with a single nanosecond pulse. We provide different arguments that the PMNS we observe originate from increasing magnetization in maxima of the interference pattern because of chemical disordering in the atomic lattice of the alloy at temperatures T higher than the critical temperature Tc for the order (B2)-disorder (A2) transition. Theoretically, our simulations of the temporal evolution of a partially ordered state at T > Tc reveal that the disordering rate is significant even below the melting threshold. Experimentally, we find that the PMNS are erasable with standard thermal annealing at T < Tc.
thin films laser patterning magnetic dots magnetic memory Opto-Electronic Advances
2020, 3(1): 01190027
