Phase Transformation of Hematite to Magnetite Under Microwave Treatment

Phase transformations of natural and synthetic hematite in aqueous Fe (II)-containing medium under the influence of microwave radiation at a temperature range from room temperature to 260°С and pressure of 6 MPa were investigated. The saturation magnetization of all initial samples was less than 1 A∙m2/kg, while the saturation magnetization of the samples after phase transformations increases significantly (i.e., up to 27 A·m2/kg). It was shown by X-ray diffraction that all samples were transformed into magnetite. Thermomagnetic curves were measured for the treated samples and Curie temperatures were determined. Curie temperatures of the samples of natural hematite were determined as 560 °C and for synthetic hematite as 559°C that are close to the Curie temperature of pure magnetite (580°C). The relatively high saturation magnetization of obtained magnetic particles makes them promising for different applications (adsorbents of radioactive waste, carriers for magnetic drug targeting, etc.). The results of this investigation could also be useful for developing new technologies for production of iron ore concentrates from the hematite-containing waste of mining and processing plants.

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Carbon-coated magnetic particles increase tissue temperatures after laser irradiation

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545815500182 ◽

2015 ◽

Vol 08 (05) ◽

pp. 1550018 ◽

Cited By ~ 1

Author(s):

Shupeng Liu ◽

Na Chen ◽

Fufei Pang ◽

Zhengyi Chen ◽

Tingyun Wang

Keyword(s):

Laser Irradiation ◽

Magnetic Particles ◽

Laser Energy ◽

Thermal Therapy ◽

Vibrating Sample Magnetometer ◽

X Ray Diffraction ◽

X Ray ◽

Fbg Sensor ◽

Transmission Electron ◽

Carbon Coated

Purpose: This work focused on the investigation the hyperthermia performance of the carbon-coated magnetic particles (CCMPs) in laser-induced hyperthermia. Materials and methods: We prepared CCMPs using the organic carbonization method, and then characterized them with transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) spectrophotometry, vibrating sample magnetometer (VSM) and X-ray diffraction (XRD). In order to evaluate their performance in hyperthermia, the CCMPs were tested in laser-induced thermal therapy (LITT) experiments, in which we employed a fully distributed fiber Bragg grating (FBG) sensor to profile the tissue's dynamic temperature change under laser irradiation in real time. Results: The sizes of prepared CCMPs were about several micrometers, and the LITT results show that the tissue injected with the CCMPs absorbed more laser energy, and its temperature increased faster than the contrast tissue without CCMPs. Conclusions: The CCMPs may be of great help in hyperthermia applications.

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In Situ X-ray Diffraction of an Arc Weld Showing the Phase Transformations of Ti and Fe as A Function of Position in the Weld Performed at a Synchrotron

Advances in X-Ray Analysis ◽

10.1007/978-1-4615-2528-8_58 ◽

1994 ◽

pp. 479-482 ◽

Cited By ~ 1

Author(s):

Joe Wong ◽

J. W. Elmer ◽

P. A. Waide ◽

E. M. Larson

Keyword(s):

Phase Transformations ◽

X Ray Diffraction ◽

X Ray

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Optimization of Microwave Pre-Cooked Conditions for Gelatinization of Adzuki Bean

Foods ◽

10.3390/foods11020171 ◽

2022 ◽

Vol 11 (2) ◽

pp. 171

Author(s):

Jianyou Zhang ◽

Xuehua Xie ◽

Lyu Zhang ◽

Yiling Hong ◽

Gaopeng Zhang ◽

...

Keyword(s):

Starch Content ◽

Polarized Light ◽

Microwave Treatment ◽

Adzuki Bean ◽

X Ray Diffraction ◽

Relative Crystallinity ◽

Soaking Time ◽

X Ray ◽

Ft Ir ◽

Microwave Time

Pre-cooked adzuki beans (Vigna angularis), which looks like dried adzuki bean, is easily cooked and preserved. This study aimed to optimize the microwave pre-cooked conditions on adzuki beans by applying the response surface methodology. The results showed that soaking time has a significant effect on the gelatinization degree of adzuki beans according to microwave time. The most suitable gelatinization and the sensory scores were obtained with a soaking time of 7.8 h, a microwave power of 830 W, and microwave time of 92 s. The pre-cooked treatment had no significant effect (p > 0.05) on the protein, free amino acid, fat and starch content of adzuki bean products. The results of SEM and polarized light microscopy showed that the surface and center of starch were damaged after microwave treatment. XRD showed that microwave pre-cooking did not change the crystal structure of starch and maintained the original order of type A structure while reducing the relative starch crystallinity. FT-IR showed that the pre-cooked treatment did not produce new structure in adzuki bean starch, but the ratio of 1047/1022 cm−1 was slightly decreased, indicating that the starch crystallization area decreased relative to the amorphous area and the relative crystallinity decreased. The results of FTIR were consistent with X-ray diffraction results. Therefore, microwaves improved the gelatinization of adzuki beans and made the pre-cooked adzuki beans more suitable.

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Magnetic and Optical Properties of Eu-doped GaN

MRS Proceedings ◽

10.1557/proc-0955-i15-01 ◽

2006 ◽

Vol 955 ◽

Author(s):

Jennifer Hite ◽

G T Thaler ◽

J H Park ◽

A J Steckl ◽

C R Abernathy ◽

...

Keyword(s):

Saturation Magnetization ◽

Room Temperature Ferromagnetism ◽

Inverse Correlation ◽

Absolute Intensity ◽

Growth Conditions ◽

X Ray Diffraction ◽

Cell Temperature ◽

X Ray ◽

Pl Intensity ◽

The Eu

ABSTRACTGaN films were doped with Eu to a concentration of ∼0.12 at. % during growth at 800°C by molecular beam epitaxy, with the Eu cell temperature held constant at 470°C. All samples were post-annealed at 675°C. The films exhibited strong photoluminescence (PL) in the red (622 nm) whose absolute intensity was a function of the Ga flux during growth, which ranged from 3-5.4×10−7 Torr. The maximum PL intensity was obtained at a Ga flux of 3.6×10−7 Torr. The samples showed room temperature ferromagnetism with saturation magnetization of ∼0.1-0.45 emu/cm3, consistent with past reports where the Eu was found to be predominantly occupying substitutional Ga sites. There was an inverse correlation between the PL intensity and the saturation magnetization in the films. X-ray diffraction showed the presence of EuGa phases under all of our growth conditions but these cannot account for the observed magnetic properties.

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Characterization of the Phase Transformations in the Shape Memory Alloy Ni-36 at.% Al

MRS Proceedings ◽

10.1557/proc-246-61 ◽

1991 ◽

Vol 246 ◽

Cited By ~ 6

Author(s):

J.A. Horton ◽

E.P. George ◽

C.J. Sparks ◽

M.Y. Kao ◽

O.B. Cavin ◽

...

Keyword(s):

High Temperature ◽

Shape Memory ◽

Phase Transformations ◽

Hot Extrusion ◽

Exothermic Peak ◽

Nickel Aluminum ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Transmission Electron

AbstractA survey by differential scanning calorimetry (DSC) and recovery during heating of indentations on a series of nickel-aluminum alloys showed that the Ni-36 at.% Al composition has the best potential for a recoverable shape memory effect at temperatures above 100°C. The phase transformations were studied by high temperature transmission electron microscopy (TEM) and by high temperature x-ray diffraction (HTXRD). Quenching from 1200°C resulted in a single phase, fully martensitic structure. The initial quenched-in martensites were found by both TEM and X-ray diffraction to consist of primarily a body centered tetragonal (bct) phase with some body centered orthorhombic (bco) phase present. On the first heating cycle, DSC showed an endothermic peak at 121°C and an exothermic peak at 289°C, and upon cooling a martensite exothermic peak at 115° C. Upon subsequent cycles the 289°C peak disappeared. High temperature X-ray diffraction, with a heating rate of 2°C/min, showed the expected transformation of bct phase to B2 between 100 and 200°C, however the bco phase remained intact. At 400 to 450°C the B2 phase transformed to Ni2Al and Ni5Al3. During TEM heating experiments a dislocation-free martensite transformed reversibly to B2 at temperatures less than 150°C. At higher temperatures (nearly 600°C) 1/3, 1/3, 1/3 reflections from an ω-like phase formed. Upon cooling, the 1/3, 1/3, 1/3 reflections disappeared and a more complicated martensite resulted. Boron additions suppressed intergranular fracture and, as expected, resulted in no ductility improvements. Boron additions and/or hot extrusion encouraged the formation of a superordered bct structure with 1/2, 1/2, 0 reflections.

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THE GIANT MAGNETOSTRICTION OF [Fe/Tb/Fe/Dy]n MULTILAYER FILMS UNDER DIFFERENT ANNEALING TEMPERATURE

Surface Review and Letters ◽

10.1142/s0218625x0901238x ◽

2009 ◽

Vol 16 (01) ◽

pp. 123-126 ◽

Cited By ~ 1

Author(s):

X. D. LI ◽

Z. J. ZHAO ◽

T. FENG ◽

L. K. PAN ◽

S. M. HUANG ◽

...

Keyword(s):

Saturation Magnetization ◽

Annealing Temperature ◽

Multilayer Films ◽

X Ray Diffraction ◽

X Ray ◽

Low Field ◽

Giant Magnetostriction

The effect of annealing temperature on the magnetic and giant magnetostriction (GMS) of [ Fe / Tb / Fe / Dy ]n multilayer films were investigated. X-ray diffraction showed that the multilayer films' microstructures were still in amorphous at annealing temperature 300°C. The multilayer films began to crystalline at annealing temperature 400°C. The saturation magnetization of multilayer films increased by the increasing annealed temperature. The coercivity first decreased at annealing temperature 300°C and then increased when the annealing temperature was higher than 400°C. The multilayer films had good low-field GMS, and the magnetostriction of the multilayer films increased by the increasing annealing temperature.

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In situ high-temperature X-ray diffraction study of phase transformations in silver behenate

Powder Diffraction ◽

10.1154/1.1913713 ◽

2005 ◽

Vol 20 (02) ◽

pp. 94-96 ◽

Cited By ~ 2

Author(s):

Thomas N. Blanton ◽

Swavek Zdzieszynski ◽

Michael Nicholas ◽

Scott Misture

Keyword(s):

High Temperature ◽

Phase Transformations ◽

Diffraction Study ◽

X Ray Diffraction ◽

X Ray

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Structural dynamics of an iron molybdate catalyst under redox cycling conditions studied with in situ multi edge XAS and XRD

Physical Chemistry Chemical Physics ◽

10.1039/d0cp01506g ◽

2020 ◽

Vol 22 (20) ◽

pp. 11713-11723 ◽

Cited By ~ 1

Author(s):

Abhijeet Gaur ◽

Matthias Stehle ◽

Kristian Viegaard Raun ◽

Joachim Thrane ◽

Anker Degn Jensen ◽

...

Keyword(s):

Phase Transformations ◽

Absorption Spectroscopy ◽

Structural Dynamics ◽

Redox Cycling ◽

X Ray Diffraction ◽

Iron Molybdate ◽

X Ray ◽

X Ray Absorption

Combination of in situ multi-edge X-ray absorption spectroscopy at the Mo K- and Fe K-edges in combination with X-ray diffraction successfully uncovered structural dynamics and phase transformations of an iron molybdate catalyst during redox cycling.

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