Non-volatile magnon transport in a single domain multiferroic

Antiferromagnets have attracted significant attention in the field of magnonics, as promising candidates for ultralow-energy carriers for information transfer for future computing. The role of crystalline orientation distribution on magnon transport has received very little attention. In multiferroics such as BiFeO3 the coupling between antiferromagnetic and polar order imposes yet another boundary condition on spin transport. Thus, understanding the fundamentals of spin transport in such systems requires a single domain, a single crystal. We show that through Lanthanum (La) substitution, a single ferroelectric domain can be engineered with a stable, single-variant spin cycloid, controllable by an electric field. The spin transport in such a single domain displays a strong anisotropy, arising from the underlying spin cycloid lattice. Our work shows a pathway to understanding the fundamental origins of magnon transport in such a single domain multiferroic

Reversibly controlled ternary polar states and ferroelectric bias promoted by boosting square???tensile???strain

Interaction between dipoles often emerges intriguing physical phenomena, such as exchange bias in the magnetic heterostructures and magnetoelectric effect in multiferroics, which lead to advances in multifunctional heterostructures. However, the defect-dipole tends to be considered the undesired to deteriorate the electronic functionality. Here, we report deterministic switching between the ferroelectric and the pinched states by exploiting a new substrate of cubic perovskite, BaZrO3, which boosts square-tensile-strain to BaTiO3 and promotes four-variants in-plane spontaneous polarization with oxygen vacancy creation. First-principles calculations propose a complex of an oxygen vacancy and two Ti3+ ions coins a charge-neutral defect-dipole. Cooperative control of the defect-dipole and the spontaneous polarization reveals ternary in-plane polar states characterized by biased/pinched hysteresis loops. Furthermore, we experimentally demonstrate that three electrically controlled polar-ordering states lead to switchable and non-volatile dielectric states for application of non-destructive electro-dielectric memory. This discovery opens a new route to develop functional materials via manipulating defect-dipoles and offers a novel platform to advance heteroepitaxy beyond the prevalent perovskite substrates

Photochemically driven solid electrolyte interphase for extremely fast-charging lithium-ion batteries

Extremely fast charging such as charging 80% of capacity within 15 min is a pressing requirement for current lithium-ion battery technology. Here the authors achieve this by incorporating an artificial solid-electrolyte interphase rich in inorganic components on the graphite electrode. Extremely fast charging (i.e. 80% of storage capacity within 15 min) is a pressing requirement for current lithium-ion battery technology and also affects the planning of charging infrastructure. Accelerating lithium ion transport through the solid-electrolyte interphase (SEI) is a major obstacle in boosting charging rate; in turn, limited kinetics at the SEI layer negatively affect the cycle life and battery safety as a result of lithium metal plating on the electrode surface. Here, we report a gamma-ray-driven SEI layer that allows a battery cell to be charged to 80% capacity in 10.8 min as determined for a graphite full-cell with a capacity of 2.6 mAh cm(-2). This exceptional charging performance is attributed to the lithium fluoride-rich SEI induced by salt-dominant decomposition via gamma-ray irradiation. This study highlights the potential of non-electrochemical approaches to adjust the SEI composition toward fast charging and long-term stability, two parameters that are difficult to improve simultaneously in typical electrochemical processes owing to the trade-off relation.

Influence of organic matter on seawater battery desalination performance

A rechargeable seawater battery desalination (SWB-D) system stores energy in a battery cell while removing salts from saline water via a sodium superionic conductor membrane and an anion exchange membrane. However, the electrochemical performance often degrades owing to the organic fouling generated on the ion exchange membranes. In this study, we investigated the fouling behavior of the SWB-D system by individually dissolving three different types of organic matter-humic acid, sodium alginate, and bovine-serum-albumin. In terms of the salt-removal performance of the SWB-D system, gradual degradation was observed over three charging cycles using hydrophobic humic acid (-13 %) and bovine-serum-albumin (-18 %), whereas no degradation was caused by hydrophilic sodium alginate. Continuous water flow mitigated the fouling behavior, and a large volume of saline water enabled longer charging. The increase in the electrical resistance of the SWB-D system was measured in the presence of organic matter using electrochemical impedance spectroscopy and the four-electrode method. Additionally, the presence of fouling layer was identified using field-emission scanningelectron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectrometry. In conclusion, the results demonstrated that the hydrophobic organic matter in the feed water could be unfavorable when operating the SWB-D system

Performance evaluation of organic matter adsorption from actual graywater using GAC: Orbitrap

The complex combination of organic contaminants in the wastewater made water treatment challenging; hence, organic matter in water bodies is usually measured in terms of organic carbon. Since it is important to identify the types of compounds when deciding suitable treatment methods, this study implemented a quantitative and qualitative analysis of the organic matter content in an actual graywater sample from Ulsan, Republic of Korea using mass spectroscopy (MS). The graywater was treated using adsorption to remove the organic contaminants. Using orbitrap MS, the organic matter content between an untreated graywater and the treated effluent were compared which yielded a significant formula count difference for the samples. It was revealed that CHON formula has the highest removal count. Isotherm studies found that the Freundlich equation was the best fit with a coefficient of determination (R2) of 0.9705 indicating a heterogenous GAC surface with a multilayer characteristic. Kinetics experiments fit the pseudo-second order equation with an R2 of 0.9998 implying that chemisorption is the rate-determining step between the organic compounds and GAC at rate constant of 52.53 g/mg???h. At low temperatures, the reaction between GAC and organic compounds were found to be spontaneous and exothermic. The conditions for optimization were set to achieve a maximum DOC and TN removal which yielded removal percentages of 94.59% and 80.75% for the DOC and TN, respectively. The optimum parameter values are the following: pH 6.3, 2.46 g of GAC for every 30 mL of graywater sample, 23.39 hrs contact time and 38.6 Celcius degree