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The atmospheric chemical vapor deposition (APCVD) method has been widely applied to synthesize high-quality two-dimensional materials. GeTe has many intriguing properties, such as phase transition, thermoelectric and ferroelectricity, which allow unique opportunities for functional ferroelectric devices. Here, we systematically investigated effects of various parameters during the growth of α-GeTe nanosheets on mica by APCVD. Single-crystal α-GeTe nanosheets possess a lateral size of up to ∼30 μm and a thickness as low as ∼8.6 nm. It was found that substrate pre-annealing significantly impacted the nucleation density of α-GeTe nanosheets. Furthermore, the room-temperature ferroelectric properties of α-GeTe nanosheets grown by CVD are reported for the first time. This work offers an effective accessible method for the controllable growth of large-size 2D α-GeTe to explore its fascinating multiferroic properties. [ABSTRACT FROM AUTHOR]

The van der Waals interface structures and behaviors are of great importance in determining the physical properties of two-dimensional atomic crystals and their heterostructures. The delicate interfacial properties are sensitively dependent on the mechanical behaviors of atomically thin films under external strain. Here, we investigated the strain-engineered rippling structures at the CVD-grown bilayer-MoS2 interface with advanced atomic force microscopy (AFM). The in-plane compressive strain is sequentially introduced into the 1L-substrate and 2L-1L interface of bilayer-MoS2 flakes via a fast-cooling process. The thermal strain-engineered rippling structures were directly visualized at the central 2H- and 3R-MoS2 bilayer regions with friction force microscopy (FFM) and bimodal AFM techniques. These rippling structures can be further artificially manipulated into the beating-like rippling features and fully erased via the contact mode AFM scanning. Our results shed lights on the strain-engineered interfacial structures of two-dimensional materials and also inspire the further investigation on the interface engineering of their electronic and optical properties. [ABSTRACT FROM AUTHOR]

Seagrass litter is a crucial autochthonous source of sediment organic carbon (Corg) that contributes to Corg storage in coastal ecosystems. However, our understanding of seagrass litter decomposition effects on sediment Corg sequestration and the factors influencing the capacity for autochthonous carbon sequestration remains limited. We investigated Zostera marina litter decomposition dynamics in eelgrass meadows along the Korean coast by monitoring changes in the remaining litter mass and autochthonous Corg during the decomposition process. We used a double‐component exponential decay models to characterize the decomposition dynamics and estimate the autochthonous Corg remaining. We also identified potential factors affecting litter decay and Corg accumulation in sediments by examining site‐specific physicochemical properties. Our findings revealed that double‐component models effectively characterized litter decomposition dynamics and indicated greater preservation of litter‐derived slowly degrading Corg in sediments. The reduced decomposition of litter materials owing to low oxygen availability in the muddy sediments led to greater retention of litter mass and litter‐derived Corg in sediments. The anoxic conditions of below‐ground litterbags, compared with above‐ground litterbags, could be alleviated by the oxygen transport through fresh Z. marina roots, thereby potentially stimulating the microbial decomposition of Z. marina below‐ground litter materials at these sites. Our findings highlight the importance of understanding litter decomposition dynamics to accurately assess the carbon sink capacity of seagrass meadows, and demonstrate that physicochemical properties can influence seagrass litter decomposition. [ABSTRACT FROM AUTHOR]

In this work, four complexing agents participated in the synthesis of Ni0.2Zn0.2Co0.6Fe2O4 ferrites by sol-gel route. The X-ray diffraction (XRD) pattern showed that samples had formed spinel phase. The Fourier transform infrared (FTIR) spectra of samples showed two absorption bands around 400 cm−1 and 600 cm−1, which are the characteristics of spinel ferrites. SEM micrographs showed that the prepared particles had different shape. Vibrating sample magnetometer was used to characterize magnetic performances. The prepared samples showed typical hysteresis behaviors at room temperature. The Ni0.2Zn0.2Co0.6Fe2O4 ferrite sample prepared with egg white as a complexing agent had high coercivity (1365.52 Oe) and remanent magnetization (23.95 emu/g), which indicated that the sample had a potential applications for magnetic storage devices. The sample prepared with egg white had a coercivity six times higher than coercivities (168.44–200.47 Oe) of other samples. These findings revealed that egg white is a suitable complexing agent to prepare Ni0.2Zn0.2Co0.6Fe2O4 hard ferrite by sol-gel route. The optical properties are characterized using PL emission spectra and UV–visible absorption spectrum. From the optical band gap (Eg) value, the sample has the characteristics of a semiconductor material. [ABSTRACT FROM AUTHOR]

Sr2+ ions-substituted cobalt ferrite having the composition formula SrxCo1−xFe2O4 (x = 0.05, 0.10, 0.15, and 0.20) was synthesized with sol–gel method. X-ray diffraction (XRD) patterns proved that the samples had a spinel structure. The Fourier-transform infrared (FTIR) spectra showed that the samples have two characteristic bands about the intrinsic vibrations of spinel ferrite. The morphology and chemical elements were tested by scanning electron microscope (SEM) and energy-dispersive spectrometer (EDS). The elemental state of annealed samples was examined by X-ray photoelectron spectroscopy (XPS). The magnetic data showed the coercivity increased from 954.33 Oe to 1545.54 Oe when the Sr2+ ions content increased. The optical absorption properties of annealed samples were investigated by UV–Vis spectroscopy. Complex impedance spectroscopy showed that grain resistance of Sr0.10Co0.90Fe2O4 sample was 443.9 Ω. [ABSTRACT FROM AUTHOR]