The working solutions of metal ions were prepared by appropriate dilutions of the stock solution immediately prior to their use. 2.2. Nano magnetite-Chitosan films (NMag-CS) preparation Magnetite nanoparticles prepared by co-precipitation method obtained according to methodology previously described in other work [22] with average size2- 5 nm.
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Film preparation in a pure Ar atmosphere is first investigated. Fig. 1 depicts the XRD pattern of the Fe–Ge–O thin films as a function of Ge concentration. The dashed area is enlarged in the inset for easier viewing. The Ge concentration is varied from 0 to 9 at.% by adopting different Ge chips.The phase mixture of wüstite and magnetite is first observed at 0 …
The goals of this study were to develop a better understanding of the mechanism of corrosion and film growth, and to derive an electrical model for the interface which subsequently might be used to predict the Growth of porous magnetite films on carbon steel 297 p r o p e r t i e s o f films f o r m e d in crevices in o p e r a t i n g P W R s ...
The H 2 O-concentration-dependent changes in the Fe 2+ concentration can also explain why the films grown with the 0 and 0.125 wt% H 2 O solutions have an out-of-plane lattice parameter equivalent to that of the bulk magnetite (∼0.84 nm).
Fig. 2. A schematic diagram of the magnetite deposition loop system. 2.3 Microstructure of film and magnetite deposits The wettability and surface roughness of film were measured using contact angle and surface profiler. In addition, the chemical species of film was observed using X-ray photoelectron spectroscopy (XPS) analysis.
In addition, the best magnetite coating is obtained using a blackening bath with a nitrate concentration between 25 % and 50 %, at a temperature of 140 °C and with a dwell time between 15 minutes and 30 minutes. reaction mechanism involved in the hot alkaline blackening Keywords— magnetite thin film; steel substrate; hot
The concentration of oxygen dissolved in LBE during the entire test were monitored by ... °C for 1000 h. For the condition of Co of 5×10-6 wt.%, the detected peaks mainly match with the characteristic peaks of magnetite (Fe 3 O 4) and Fe-Cr spinel. It is hard to distinguish the magnetite and spinel by XRD since the magnetite is an inverse ...
Consequently, Raman spectra of the magnetite films were acquired using a 532 nm diode laser as the excitation source. The power of the laser was set to 5 mW which was below the determined damage threshold. The measurements were performed with the 100x objective lens and a 600 g/mm grating (BLZ = 500 nm) with a CCD camera as the detector ...
magnetite coating improves the wear resistance and corrosion properties of the steel substrate. In addition, the best magnetite coating is obtained using a blackening bath with a nitrate …
Moreover, the high concentration of magnetite in the film impedes its shrinkage, as the introduction of solid particles into a flexible material reduces its flexibility; on the other hand, the blocking of PVA functional groups due to van der Waals (or hydrogen) interactions with Fe 3 O 4 particles may occur. Practically all dependences for ...
ions in LEP films was determined by CEMS, and the surface morphology of the film was observed by AFM. Electrical resistance and ac-susceptibility of LEP films were measured between 15 K and 295 K, confirming the existence of the low temperature transition (Verwey transition)9 of magnetite and suggesting fine structure of LEP films. Experimental ...
These figures also showed the magnetite films thickness as a function of anodization time for 0.1 A/cm2 applied current density in 5 % NaOH concentration under 200 oC reaction time. It showed that magnetite films thickness increased with increase in anodization time.
The magnetite film formed over the carbon steel surfaces at the high temperatures, under reducing and alkaline conditions is a protective layer with low defect concentration. …
Films prepared of hydroxyethyl cellulose/bentonite/magnetite hybrid materials showed antifungal effect against C. albicans and killed fungi more effectively than the hydroxyethyl cellulose ...
MR effect of magnetite films prepared by the ferrite plating. The magnetite films synthesized by the ferrite plating were actually composed of Fe30 4 and y-FezO/ The ratio in the films was changed by the degree of oxidation. In this paper, we investigated the dependence of magnetic and electrical properties of Fe3_,04 films on a concentration ...
However, as long as a high caustic concentration exists, the magnetite is constantly dissolved, causing a loss of base metal and eventual failure (see Figure 11-2). ... In new systems, or those considered to have a poorly formed magnetite film, the minimum feed rate is 400 ppm as hydroquinone. pH should be maintained at 10.0.
Study of Magnetite Film Formation at Metal-Scale Interface During Cooling of Steel Products* J. Baud,t A. Ferrier,t and J. Manenct Received October 20, 1977 A thin layer of magnetite is sometimes observed in the scales of hot-rolled ... 15 Iron concentration in these samples was verified by measur- ing the lattice parameter. Decomposition ...
The formation of a healthy magnetite (Fe₃O₄) film on the internal surfaces of boiler tubes is crucial for ensuring their longevity and operational efficiency.
Magnetizations of films were characterized with a superconducting quantum interference device (SQUID) magnetometer. The film thicknesses were evaluated from cross …
The proeutectoīd reaction which, during cooling, produces an increase in the oxygen concentration of the wustite in contact with the metal favors the subsequent growth of the …
Film composite materials were obtained using atactic polystyrene (М n = 1.4 × 10 5, M w /M n = 1.64; Aldrich, Germany) and bentonite (Sigma-Aldrich, United States) modified with magnetite.To obtain magnetized clay, an aqueous solution containing iron chloride and sulfate at a Fe 3+ /Fe 2+ molar ratio of 2 : 1 was prepared, and bentonite was dispersed in this solution …
In a new or cleaned boiler, the initial corrosion process produces this magnetite film as a tenacious layer at the steel surface. Consequently, the corrosion reaction is self-inhibiting. ... The caustic concentration can get as high as 10,000 to 100,000 ppm. Localized attack due to extremely high pH (12.9+) will occur as will the formation of ...
In new systems, or those considered to have a poorly formed magnetite film, the minimum feed rate is 400 ppm as hydroquinone. pH should be maintained at 10.0. No matter which …
Ge concentration in the films ranged from 0 to 14at% with the use of different Ge chips. The X-ray diffraction result revealed that as-deposited films were structurally changed with respect to Ge concentration, and a magnetite film was successfully obtained at 5at%Ge and room temperature,
The effect of initial Cu 2+ concentration on crosslinked CMC-g-CMPVA (iii) film and (iv) beads loaded with various magnetite Fe 3 O 4 nanoparticles. [Conditions for adsorption process: Initial Cu 2+ concentration of 25–200 mg/L, …
Locally equilibrium thermodynamic model is developed to describe the formation and dissolution of the outer magnetite layer of an oxide film on the steel surface in contact …
These experiments showed that dissolution of deposited magnetite films occurred via a reductive dissolution process providing the electrode potential was <0 mV (vs SCE at 25 C). ... An active-to-passive transition was observed in solutions with a concentration ratio of oxalate to EDTA ≳ 4. A pitting potential of ∼ + 600 mV was obtained in ...
Keywords Thin films · Magnetite · Dip coating · Ferrofluids · Möss spectroscopy This article is part of the Topical Collection on Proceedings of the 15th Latin American Conference on the Applications of the Möss Effect (LACAME 2016), 13-18 November 2016, Panama City, Panama Edited by Juan A. Jaén A. A. Velásquez avelas26@eafit ...
The film samples were prepared as pieces with thicknesses in the range of 0.3–0.4 mm. The film pieces with different MNPs concentrations were installed individually inside optical cryostat of type LN Oxford DN1704 equipped with quartz windows. A water filter was used to absorb the thermal effect of the white light from the tungsten lamp.
Magnetite app in ars the oxygen-rich part near the wustite-magnetite interface, while a film ofa new phase appears t the metal-wustite interface. According to certain authors 6-~1 this …
Cyclic voltammetry at low V(V) concentration shows that it is electroactive only at pH ... Fig. 3c shows a magnetite film, revealing the presence of globule-like surface structures; the bright areas at the borders are larger globular structures. It is clearly seen that the MFE structure is not influenced by the underlying surface.
Abstract: Magnetite (Fe3O4) nanoparticles were successfully synthesized by a sol–gel method. The obtained nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive analysis by X-ray (EDAX), transmission electron microscopy (TEM), superconducting quantum interference device (SQUID) and …
The concentration of total chlorine in the system was the sum of the chloride concentration and double concentration of DCA. PS, sulfate, ferrous ion and total dissolve iron were measured using a Hach DR2800 spectrophotometer (Loveland, CO) and detailed methods were described in Zhong et al. (2015) .
Thin films of magnetite (Fe 3 O 4) with thicknesses in the range 10–1000 nm have been produced by the XeCl excimer laser ... 111 126 113 emphasis was given to obtaining magnetite thin films using low fluences in order to reduce the boulder concentration on the film surface. The sub- strate was heated resistively and its temperature was ...
A thin layer of magnetite is sometimes observed in the scales of hot-rolled sheets and wire rod at the scale-metal interface. The results of this study show that this layer of magnetite is produced, during the cooling of the products, by the wustite decomposition. The time/temperature field in which it appears has been defined. This inner layer is composed of pure magnetite, in epitaxy …
A relatively low concentration of carriers (in comparison with metals) and essential change of magnetite properties at T-Tv are favourable to observe the quantum size effect and to study its influence on Vey transition . ... Magnetite films on the ceramic substrate were used to investigate the effect of the carrier concentration on the ...
