- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Preparation of thulium iron garnet ceramics and investigation of spin transport properties in thin films
摘要： Compensated ferrimagnetic thulium iron garnet ceramics were prepared by the sol-gel method, which is significantly better than conventional solid-state reactions. Saturation magnetization yielded a maximum of 16.7 emu/g for specimens sintered at 900 °C. Subsequently, using the TmIG bulk as the target, an epitaxial film was grown by pulsed laser deposition. Furthermore, the spin transport properties of film with an attached 5 nm-thick platinum layer were studied in terms of longitudinal spin Seebeck effect (LSSE) and spin Hall magnetoresistance (SMR). The LSSE coefficient was as high as 0.38 μV/K and the SMR was 0.0072%. These results indicated that the bulk material and thin film presented excellent qualities, which are extremely important for the fundamental investigation of novel spin transport behaviour in compensated ferrimagnetic insulators. These results also provide more alternatives for spintronic materials.
关键词： Magnetic insulators,Thulium iron garnet,Spin transport properties,Compensated ferrimagnet
更新于2025-09-23 15:22:29
-
Strong Coupling of Magnons to Microwave Photons in Three-Dimensional Printed Resonators
摘要： We report on ferromagnetic resonant mode hybridization in re-entrant cavities made with a commercial three-dimensional (3D) printer, followed by conventional 3D metalization with copper and tin. The cavity volume was only 7% that of a standard cavity resonating at the same frequency, while maintaining a high quality factor. Simulations were in very good agreement. We obtained an effective coupling of about 40 MHz in two cavities at room temperature. These experimental results demonstrate the utility of tunable filters based on complex 3D printed cavities.
关键词： magnon photon polariton,3D Cavity spintronic,Yttrium Iron Garnet,3D printing,tunable filter
更新于2025-09-23 15:22:29
-
Photocatalytic Degradation of Estriol Using Iron-Doped TiO2 under High and Low UV Irradiation
摘要： Iron-doped TiO2 nanoparticles (Fe-TiO2) were synthesized and photocatalitically investigated under high and low ?uence values of UV radiation. The Fe-TiO2 physical characterization was performed using X-ray Powder Diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Diffuse Re?ectance Spectroscopy (DRS), and X-ray Photoelectron Spectroscopy (XPS). The XPS evidenced that the ferric ion (Fe3+) was in the TiO2 lattice and unintentionally added co-dopants were also present because of the precursors of the synthetic method. The Fe3+ concentration played a key role in the photocatalytic generation of hydroxyl radicals (?OH) and estriol (E3) degradation. Fe-TiO2 accomplished E3 degradation, and it was found that the catalyst with 0.3 at.% content of Fe (0.3 Fe-TiO2) enhanced the photocatalytic activity under low UV irradiation compared with TiO2 without intentionally added Fe (zero-iron TiO2) and Aeroxide? TiO2 P25. Furthermore, the enhanced photocatalytic activity of 0.3 Fe-TiO2 under low UV irradiation may have applications when radiation intensity must be controlled, as in medical applications, or when strong UV absorbing species are present in water.
关键词： hydroxyl radical,estriol,iron-doped TiO2,photocatalytic activity,low UV irradiation
更新于2025-09-23 15:22:29
-
Photocatalytic Mechanisms for Peroxymonosulfate Activation through the Removal of Methylene Blue: A Case Study
摘要： Industrial activity is one of the most important sources of water pollution. Yearly, tons of non-biodegradable organic pollutants are discharged, at the least, to wastewater treatment plants. However, biological conventional treatments are unable to degrade them. This research assesses the efficiency of photocatalytic activation of peroxymonosulfate (PMS) by two different iron species (FeSO4 and Fe3+-citrate) and TiO2. These substances accelerate methylene blue removal by the generation of hydroxyl and sulfate radicals. The required pH and molar ratios PMS:Fe are crucial variables in treatment optimization. The kinetic removal is reduced by the appearance of scavenger reactions in acidic and basic conditions, as well as by the excess of PMS or iron. The best performance is achieved using an Fe3+-citrate as an iron catalyst, reaching the total removal of methylene blue after 15 min of reaction, with a molar ratio of 3.25:1 (1.62 mM of PMS and 0.5 mM Fe3+-citrate). Fe3+-citrate reached higher methylene blue removal than Fe2+ as a consequence of the photolysis of Fe3+-citrate. This photolysis generates H2O2 and a superoxide radical, which together with hydroxyl and sulfate radicals from PMS activation attack methylene blue, degrading it twice as fast as Fe2+ (0.092 min?1 with Fe2+ and 0.188 min?1 with Fe3+-citrate). On the other hand, a synergistic effect between PMS and titanium dioxide (TiO2) was observed (SPMS/TiO2/UV-A = 1.79). This synergistic effect is a consequence of PMS activation by reaction with the free electron on the surface of TiO2. No differences were observed by changing the molar ratio (1.04:1; 0.26:1 and 0.064:1 PMS:TiO2), reaching total removal of methylene blue after 80 min of reaction.
关键词： iron activation,peroxymonosulfate,sulfate radicals,synergistic effect,TiO2 activation,dye
更新于2025-09-23 15:22:29
-
Facile Preparation of Unsubstituted Iron(II) Phthalocyanine/Carbon Nitride Nanocomposites: A Multipurpose Catalyst with Reciprocally Enhanced Photo/Electrocatalytic Activity
摘要： The development of new catalytic materials is conducive to solving the global energy crisis and environmental problems. In this work, multipurpose catalyst unsubstituted iron(II) phthalocyanine/carbon nitride nanosheet (FePc/CN) nanocomposites were prepared by utilizing concentrated sulfuric acid as an ideal solvent of CN and unsubstituted FePc. Such FePc/CN nanocomposites exhibited improved photo/electrocatalytic activity which was enhanced reciprocally: the photocatalytic activity of CN was promoted by FePc anchoring, and the electrocatalytic activity of FePc was improved by CN doping. The photocatalytic performance of FePc/CN?0.3 nanocomposites was about 6.4 and 1.7 times as high as FePc and CN, which was attributed to two reasons: (1) the anchoring FePc on CN extended the visible-light absorption region of CN, (2) the electron transfer from excited FePc to CN hindered charge carriers recombination and thus enhanced the photoinduced carrier separation efficiency. Relative to FePc and CN, the onset potential of FePc/CN?0.3 was positively shifted by 52 and 174 mV, such higher oxygen reduction reaction activity was due to the uniform dispersion of FePc on the supporting material CN without aggregation, which led to improved conductivity and stability of nanocomposites. This approach will contribute to an inexpensive and convenient synthetic strategy of transition-metal-based nanostructures for functional applications in photovoltaic, electrochemical, and catalytic fields.
关键词： Unsubstituted iron(II) phthalocyanine,Oxygen reduction reaction,Multipurpose catalyst,Photocatalytic performance,Carbon nitride nanosheet
更新于2025-09-23 15:22:29
-
Quantification and analysis of geomorphic processes on a recultivated iron ore mine on the Italian island of Elba using long-term ground-based lidar and photogrammetric SfM data by a UAV
摘要： This study focuses on the quanti?cation and analysis of geomorphic processes on the barely vegetated slopes of a recultivated iron ore mine on the Italian island of Elba using photographs from terrestrial laser scanning (TLS) and digital photogrammetry by an unmanned aerial vehicle (UAV) over a period of 5 1/2 years. Beside this, the study tried to work out the potential and the limitations of both methods to detect surface changes by geomorphic process dynamics within a natural environment. Both UAV and TLS show the pattern of the erosion and accumulation processes on the investigated slope quite well, but the calculated amounts differ clearly between the methods. The reasons for these differences could be found in the different accuracies (variable level of detections) of the methods and the different viewing geometries. Both effects have an impact on the detectable process dynamics over different timescales on the slope and their calculated amounts, which in both cases can lead to an underestimation of erosion and accumulation by ?uvial processes.
关键词： terrestrial laser scanning,erosion,geomorphic processes,UAV,recultivated iron ore mine,accumulation,digital photogrammetry
更新于2025-09-23 15:21:21
-
[IEEE 2018 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) - Ann Arbor, MI (2018.7.16-2018.7.18)] 2018 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP) - Nonlinear Equivalent-Circuit Model for Thin-Film Magnetic Material Based RF Devices
摘要： A nonlinear equivalent-circuit model is developed for thin-film magnetic material based RF devices such as frequency-selective limiter (FSL) and signal-to-noise enhancer (SNE). The ferromagnetic resonance is modeled by a RLC parallel circuit with parameters derived from Kittel’s equations. The nonlinear effect in magnetic material is represented by a pendulum model that predicts cross-frequency coupling as well as parametric oscillations of spins. The coupling of spin waves in different orders is also modeled by coupled nonlinear pendulum resonators with the exchange coupling between the spins represented by coupling inductors. The measurement results of a FSL in literature are used as a reference, and the model successfully predicts the threshold power level, nonlinear insertion loss, and frequency selectivity of the device.
关键词： Ferromagnetic resonance (FMR),Yttrium iron garnet (YIG),nonlinear model,thin film,frequency selective limiter (FSL)
更新于2025-09-23 15:21:21
-
Flexible electrochromic tungsten/iron mixed oxide films synthesized by an atmospheric pressure plasma jet
摘要： Flexible electrochromic organo-tungsten- iron oxide (WFexOyCz) films are rapidly deposited onto flexible (60 Ω/□ polyethylene terephthalate/indium tin oxide; PET/ITO) substrates by a low temperature-atmospheric pressure-plasma polymerization method with an atmospheric pressure plasma jet (APPJ) for a short exposed duration of 48 s. The precursor vapors of tungsten hexacarbonyl [W(CO)6] and biscyclopentadienyl iron [ferrocene; Fe(C5H5)2] are mixed with O2 gases at various gas flow rates, injected into air plasma jet and sprayed onto PET/ITO substrates at room temperature (~23oC) and at atmospheric pressure (1.013 × 105 Pa). Flexible electrochromic WFexOyCz films are synthesized with a specific addition of oxygen gases with superior lithium electrochromic properties as demonstrated by a potential sweep alternating between -1 V and 2 V at a scan rate of 40 mV/s in a 1 M LiClO4-propylene carbonate electrolyte. With amorphous WFexOyCz films produced with an APPJ by adding oxygen gases at a specific flow rate of 0.5 sccm, a high value in oxygen deficiency up to 0.189 allows more Li+ ions to intercalate into and deintercalate out of the film. Significant coloration and bleaching are proven by the high values in optical transmittance modulation (ΔT) of up to 70.3%, optical density (ΔOD) up to 0.77 and color efficiency (η) up to 61.3 cm2/C, at a wavelength of 800 nm, respectively.
关键词： Electrochromic materials,Iron oxide,Tungsten oxide,Flexible electrochromic film,Atmospheric pressure plasmas,Plasma polymerization
更新于2025-09-23 15:21:21
-
AIP Conference Proceedings [Author(s) PROCEEDINGS OF THE INTERNATIONAL CONFERENCE OF COMPUTATIONAL METHODS IN SCIENCES AND ENGINEERING 2017 (ICCMSE-2017) - Thessaloniki, Greece (21–25 April 2017)] - Geomorphic record of historical ferrous metallurgy in Ma?a Panew and Czarna River valleys (Poland) – Analysis of DEM from airborne LiDAR
摘要： Ferrous metallurgy, through the centuries of its activity contributed the transformation of the natural landscape. We can find information on the time of functioning of iron works in historical sources. Among historians, there is an opinion that the traces of iron works activity are not visible in the field, but using GIS methods we can identify different types of objects related to ferrous metallurgy like dams, canals, smelter ponds and charcoal kilns. The aim of the study was to identify imprints of ferrous metallurgy in relief of two valleys in Southern Poland. The study was conducted in Ma?a Panew and Czarna River valleys where ferrous metallurgy, based on historical sources, has started in the 14th century and declined in the end of the 19th century. The tools used for identification objects related to ferrous metallurgy were standard shaded relief visualization techniques. We created models of terrain elevation with hillshading and spatial density of 0.2 m. During the analysis of DEM images we detected objects interpreted as traces of smelter ponds with accompanying dams and canals, and oval objects recognized as remnants of charcoal kilns. Large number and vast distribution of relief features related to ferrous metallurgy, charcoal kilns in particular, clearly indicate that the historical smelting and ironwork activity natural environment of studied areas was transformed. Relief of valley floors, in particular, was a subject of change.
关键词： LiDAR images,charcoal kilns,iron ponds,dikes,ferrous metallurgy
更新于2025-09-23 15:21:21
-
Exploring the potential of iron to replace ruthenium in photosensitizers: a computational study
摘要： In an effort to replace the widely used ruthenium metal complexes with low-cost, earth abundant iron complexes as photosensitizers for dye-sensitized solar cell (DSSC) applications, herein we report the computational design of heteroleptic iron complexes (FC1–3) coordinated with benzimidazole-phenylcarbene (C^N) ligands. DFT and TDDFT calculations predicted the stronger σ-donating and π-accepting nature of phenyl carbene ligands substituted with electron-withdrawing CF3, donating –N(CH3)2, and benzothiazine annulation than the imidazole carbene ligands (FC4); consequently, the metal-ligand bond distances and interactions that influence the ordering of charge transfer states with respect to metal centered states are altered in FC1–3 complexes. Detailed analysis based on energy decomposition analysis, spin density distribution analysis, and ab initio ligand field theory parameters were enabled to understand the nature of heteroleptic ligand interactions with the rest of the metal complex. The results from the study shed light on the judicious choice of ligands, as the same non-innocent ligand that is experimentally proven as favorable for Ru-dyes (TC1) is found to be detrimental for Fe-dyes (FC1). Among the complexes studied, the FC3 complex is a promising sensitizer for DSSC with 1,3MLCT energy level well separated from 3,5MC, thereby preventing the deactivation of MLCT. The outcome of the study is therefore an important step toward the development of photosensitizers based on iron metal.
关键词： DSSC,Photosensitizers,Iron,Spin states,TD-DFT,Carbene ligands,Ruthenium
更新于2025-09-23 15:21:21