Li2MnSiO4 with different crystal structure was synthesized by solid state reaction method. Their crystal structure and electrochemical properties have been characterized by X-ray diffraction and charge-discharge test....Li2MnSiO4 with different crystal structure was synthesized by solid state reaction method. Their crystal structure and electrochemical properties have been characterized by X-ray diffraction and charge-discharge test. The material prepared at 900oC in N2 atmosphere had γ-phase and its crystal structure changed to β-phase by post-heating at 400oC in air after 900oC sintering. In electrochemical measurement, two materials (γ- and β-phase) showed ~3 and ~45mAh/g, respectively. The different capacities of these two materials might be due to the change of crystal structure.展开更多
Latent heat thermal energy storage technique has demonstrate to be a better engineering option mainly due to its benefit of supplying higher energy storage density in a smaller temperature difference between retrieval...Latent heat thermal energy storage technique has demonstrate to be a better engineering option mainly due to its benefit of supplying higher energy storage density in a smaller temperature difference between retrieval and storage. For this purpose, a micro electro-mechanical system, MEMS-based heat exchanger with microencapsulated PCM (MEPCM) slurry as cold fluid, has been simulated three dimensionally. This work investigates the influence of using MEPCM-slurry on the temperature of the cold and hot fluids. The MEPCM and water properties have been considered temperature dependent. MEPCM-slurry is used with different volume fractions. The result shows that using MEPCM with 25% volume fraction leads to the improvement in fluids temperatures, that is, for hot fluid the rate of temperature reduction increases up to 23.5% and for cold fluid the rate of temperature rise decreases to 9%, compared to using only water in the MEMS.展开更多
Heusler alloys combined with MgO interfaces exhibit interfacial perpendicular magnetic anisotropy, making them attractive forenergy-efficient spintronic technologies. However, finding suitable Heusler/MgO heterostruct...Heusler alloys combined with MgO interfaces exhibit interfacial perpendicular magnetic anisotropy, making them attractive forenergy-efficient spintronic technologies. However, finding suitable Heusler/MgO heterostructures with desired properties ischallenging due to the vast range of compositions available and the complexity of interfacial structures, particularly for theemerging quaternary Heusler compounds. In this study, we report a high-throughput screening of quaternary-Heusler/MgOheterostructures for spintronic applications. By analyzing various materials descriptors, including formation energy, convex hulldistance, magnetic ordering, lattice misfit, magnetic anisotropy constant, tunnel magnetoresistance, Curie temperature, and atomicsite disordering, we identified 5 promising compounds out of 27,000 quaternary Heusler compounds. These compounds, namelyIrCrAlTi, IrCrGaTi, IrMnZnTi, OsCrAlTa, and TaGaOsCr, show potential for designing energy-efficient perpendicular magnetic tunneljunctions. This work demonstrates an efficient approach using open quantum materials repositories, effective materials descriptors,and high-throughput computational techniques to accelerate the discovery of quaternary-Heusler-based functional materials.展开更多
文摘Li2MnSiO4 with different crystal structure was synthesized by solid state reaction method. Their crystal structure and electrochemical properties have been characterized by X-ray diffraction and charge-discharge test. The material prepared at 900oC in N2 atmosphere had γ-phase and its crystal structure changed to β-phase by post-heating at 400oC in air after 900oC sintering. In electrochemical measurement, two materials (γ- and β-phase) showed ~3 and ~45mAh/g, respectively. The different capacities of these two materials might be due to the change of crystal structure.
文摘Latent heat thermal energy storage technique has demonstrate to be a better engineering option mainly due to its benefit of supplying higher energy storage density in a smaller temperature difference between retrieval and storage. For this purpose, a micro electro-mechanical system, MEMS-based heat exchanger with microencapsulated PCM (MEPCM) slurry as cold fluid, has been simulated three dimensionally. This work investigates the influence of using MEPCM-slurry on the temperature of the cold and hot fluids. The MEPCM and water properties have been considered temperature dependent. MEPCM-slurry is used with different volume fractions. The result shows that using MEPCM with 25% volume fraction leads to the improvement in fluids temperatures, that is, for hot fluid the rate of temperature reduction increases up to 23.5% and for cold fluid the rate of temperature rise decreases to 9%, compared to using only water in the MEMS.
基金This work was supported by the Academic Senate General Campus Research Grant Committee at the University of California San DiegoThis work used the Expanse cluster at San Diego Supercomputer Center through allocation DMR160045 from the Extreme Science and Engineering Discovery Environment(XSEDE),which was supported by National Science Foundation grant number#1548562,Acknowl-edgement is made to the donors of the American Chemical Society Petroleum Research Fund for partial support of this research.
文摘Heusler alloys combined with MgO interfaces exhibit interfacial perpendicular magnetic anisotropy, making them attractive forenergy-efficient spintronic technologies. However, finding suitable Heusler/MgO heterostructures with desired properties ischallenging due to the vast range of compositions available and the complexity of interfacial structures, particularly for theemerging quaternary Heusler compounds. In this study, we report a high-throughput screening of quaternary-Heusler/MgOheterostructures for spintronic applications. By analyzing various materials descriptors, including formation energy, convex hulldistance, magnetic ordering, lattice misfit, magnetic anisotropy constant, tunnel magnetoresistance, Curie temperature, and atomicsite disordering, we identified 5 promising compounds out of 27,000 quaternary Heusler compounds. These compounds, namelyIrCrAlTi, IrCrGaTi, IrMnZnTi, OsCrAlTa, and TaGaOsCr, show potential for designing energy-efficient perpendicular magnetic tunneljunctions. This work demonstrates an efficient approach using open quantum materials repositories, effective materials descriptors,and high-throughput computational techniques to accelerate the discovery of quaternary-Heusler-based functional materials.
