high pressure magnetite

high pressure magnetite

Effect of high pressure on the crystal structure and

of magnetite below 25 GPa, two possible scenarios have been heavily discussed in the literature to explain the high-pressure behavior of magnetite. The first hypothesis is a transition from the inverse type (IT) of spinel to the normal type (NT) at pressures 10–20 GPa (Rozenberg et al. 2007; Pasternak et al. 2003). Analysis of pow -

Magnetic and electronic properties of magnetite across the

Mar 14, 2019 An application of high pressure affects anomalously the behavior of magnetic and electronic properties of magnetite, ultimately leading to a structural phase transition above P ~ 25 GPa 10, 11, 12,...

High‐pressure study of stability of magnetite by

The calculations predict that the high‐pressure phase of magnetite (h‐Fe 3 O 4) becomes unstable with respect to h‐Fe 2 O 3 + FeO at pressures higher than 50 GPa. The 298 K pressure‐volume isotherm of magnetite derived from the compression experiment is given by K T = 217 (7) GPa for the fixed K ′ 0 = 4.

Abnormal Elastic and Vibrational Behaviors of Magnetite at

On the other hand, high-pressure studies at room temperature have also suggested a number of electronic, magnetic and structural transitions in magnetite including the inverse-normal spinel...

Unraveling the exhumation history of high-pressure

Aug 01, 2020 Magnetite is a ubiquitous oxide in ultramafic and mafic rocks, which is present in a large range of geological and tectonic settings. In the case of high-pressure ultramafic rocks, exhumation timing is commonly constrained by geochronometers in nearby lithologies.

Magnetite an overview ScienceDirect Topics

Limited research on the effect of high pressure and salinity on solubility of magnetite has been conducted. Measuring the magnetite solubility has proven to be more difficult than that of other oxides, such as NiO, due to the reductive dissolution of magnetite from Fe (III) to Fe (II).

Spin state of iron in Fe${}_{3}$O${}_{4}$ magnetite and $h

Apr 22, 2013 The high-pressure behavior of magnetite has been widely debated in the literature.

Water Handbook Preboiler & Industrial Boiler Corrosion

Magnetite forms on boiler system metal surfaces from the following overall reaction: 3Fe + High-pressure alkaline water is an effective means of cleaning the fireside areas. Before alkaline water is used for this purpose, a rinse should be made with fresh water of neutral pH to prevent the formation of hydroxide gels in the deposits (these

Magnetite Wikipedia

The industrial catalyst is obtained from finely ground iron powder, which is usually obtained by reduction of high-purity magnetite. The pulverized iron metal is burnt (oxidized) to give magnetite or wüstite of a defined particle size. The magnetite (or wüstite) particles are then partially reduced, removing some of the oxygen in the process.

Effect of high pressure on the crystal structure and

of magnetite below 25 GPa, two possible scenarios have been heavily discussed in the literature to explain the high-pressure behavior of magnetite. The first hypothesis is a transition from the inverse type (IT) of spinel to the normal type (NT) at pressures 10–20 GPa (Rozenberg et al. 2007; Pasternak et al. 2003). Analysis of pow -

High‐pressure study of stability of magnetite by

The calculations predict that the high‐pressure phase of magnetite (h‐Fe 3 O 4) becomes unstable with respect to h‐Fe 2 O 3 + FeO at pressures higher than 50 GPa. The 298 K pressure‐volume isotherm of magnetite derived from the compression experiment is

Abnormal elastic and vibrational behaviors of magnetite at

Sep 04, 2014 Magnetite exhibits unique electronic, magnetic, and structural properties in extreme conditions that are of great research interest. Previous studies have suggested a number of transitional models, although the nature of magnetite at high pressure remains elusive.

Equation of state of magnetite and its high-pressure

Fe 3 O 4 has been studied by high-pressure diffraction to 43 GPa. No major changes in the spinel-type structure of magnetite is observed below 21.8 GPa. At higher pressure a sluggish transition to a high-pressure modification, h-Fe 3 O 4, is observed.

Magnetite: Mineral information, data and localities.

Haavik C, Stolen S, Fjellvag H, Hanfland M, Hausermann D (2000) Equation of state of magnetite and its high-pressure modification: Thermodynamics of the Fe-O system at high pressure American Mineralogist 85 514-523: 2000: 2.3: 293: 0002403: Magnetite

(PDF) Formation of iron hydride and high-magnetite at high

Thermodynamically magnetite would dissociate to oxide mixture of FeO and Fe 2 O 3 at high pressure. Lazor et al. (2004) noted the presence of h-Fe 3 O 4 at a pressure of 19 GPa. This study finds the stability limit extended to 75 GPa. As long as both Fe and iron oxide are present the oxygen fugacity is well defined in a volume around heated iron.

Spin state of iron in Fe${}_{3}$O${}_{4}$ magnetite and $h

Apr 22, 2013 The high-pressure behavior of magnetite has been widely debated in the literature.

Magnetite Wikipedia

The industrial catalyst is obtained from finely ground iron powder, which is usually obtained by reduction of high-purity magnetite. The pulverized iron metal is burnt (oxidized) to give magnetite or wüstite of a defined particle size. The magnetite (or

Prevent Magnetite From Plugging Your Steam And Water System

Typically in these applications, low pressure is less than ~ 100psig, and low temperature is less than 120°F (49°C), with high pressures being up to 5000 psig. As mentioned above, magnetite physically can be removed from the system in three different ways:

Magnetic properties of single and multi‐domain magnetite

May 26, 2004 They found that magnetite magnetic hysteresis parameters vary <15% below 1.0 GPa, while at higher pressures, significant increases occur in bulk coercivity (Hc) and the ratio of saturation remanent magnetization (Mrs) to saturation

Metallization of magnetite (Fe3O4) under high pressure

Electrical resistivity measurements have been made on a good qualified single crystalline magnetite (Fe 3 O 4) at temperatures from 300 down to 3.0 K under pressure up to 10 GPa. A steep change in resistivity at the Verwey transition temperature has been observed at pressure below 6.5 GPa, which shows a quite distinct result reported in prior work. Moreover, the Verwey transition temperature

High-pressure Raman spectroscopic study of magnetite Fe3O4

The most striking characteristic of Raman spectroscopy of magnetite is that the pressure-induced suppression leads to a significant extinction of the Raman active mode derived from F2g symmetry. Only one peak resulting from A1g mode can be observed continuously up to 60 GPa.

Cementite Formation from Magnetite under High Pressure

Measurements have been made of the rate of Fe 3 C formation from Fe 3 O 4 powder and Fe 3 O 4 single crystals at 773 K and 1023 K under the high pressure of 0.5 and 1.0 MPa by using thermo-gravimetric method. Along with the kinetic study of Fe 3 C formation, high resolution TEM observation around the interface between Fe 3 O 4 matrix and the formed Fe 3 C have been carried out to confirm

Abnormal Elastic and Vibrational

magnetite, we have also conducted complimentary Raman spectro-scopy, synchrotron Fe K b XES, and the bulk electrical conductivity (EC) experiments at high pressures (See Methods and SI, Fig. 3, S6– 7)28,29. Analyses of the high-pressure Raman spectra show three dis-tinct Raman bands that can be assigned to A 1g, T 2g, and E g modes of

Metallization of magnetite (Fe3O4) under high pressure

Electrical resistivity measurements have been made on a good qualified single crystalline magnetite (Fe 3 O 4) at temperatures from 300 down to 3.0 K under pressure up to 10 GPa. A steep change in resistivity at the Verwey transition temperature has been observed at pressure below 6.5 GPa, which shows a quite distinct result reported in prior work. Moreover, the Verwey transition temperature

In situ observation of the breakdown of magnetite (Fe3O4

the high-pressure BreAKdoWn oF mAgnetite Two experiments were performed following similar pressure-temperature paths; the paths for Mag_1 and Mag_2 are presented in Figure 1. Sample Mag_1 was compressed to ∼12 GPa (i.e., beyond the stability field of magnetite, Schollenbruch et al. 2011) and then heated up to a temperature of about 1200 K. In a

Magnetite: Mineral information, data and localities.

Haavik C, Stolen S, Fjellvag H, Hanfland M, Hausermann D (2000) Equation of state of magnetite and its high-pressure modification: Thermodynamics of the Fe-O system at high pressure American Mineralogist 85 514-523: 2000: 2.3: 293: 0002403: Magnetite

Abnormal elastic and vibrational behaviors of magnetite at

Sep 04, 2014 On the other hand, high-pressure studies at room temperature have also suggested a number of electronic, magnetic, and structural transitions in magnetite including the inverse-normal spinel transition 9,14,15, the high-spin to intermediate-spin transition 16,19, the enhanced delocalization or charge ordering of the 3d electrons of the iron

Cementite Formation from Magnetite under High Pressure

Measurements have been made of the rate of Fe 3 C formation from Fe 3 O 4 powder and Fe 3 O 4 single crystals at 773 K and 1023 K under the high pressure of 0.5 and 1.0 MPa by using thermo-gravimetric method. Along with the kinetic study of Fe 3 C formation, high resolution TEM observation around the interface between Fe 3 O 4 matrix and the formed Fe 3 C have been carried out to confirm

Magnetite Wikipedia

Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe 3 O 4.It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. It is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of

Abnormal Elastic and Vibrational

magnetite, we have also conducted complimentary Raman spectro-scopy, synchrotron Fe K b XES, and the bulk electrical conductivity (EC) experiments at high pressures (See Methods and SI, Fig. 3, S6– 7)28,29. Analyses of the high-pressure Raman spectra show three dis-tinct Raman bands that can be assigned to A 1g, T 2g, and E g modes of

Experimental determination of the reaction 2magnetite

2almandine + 02 at high pressure on the magnetite-hematite buffer DlNrnr, E. Hlnr,ov Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, Indiana 47907, U.S.A. Roennr C. NrcwroN Department of the Geophysical Sciences, The University of Chicago, 5734 South Ellis Avenue, Chicago, Illinois 60637, U.S.A. Ansrucr

Prevent Magnetite From Plugging Your Steam And Water System

Typically in these applications, low pressure is less than ~ 100psig, and low temperature is less than 120°F (49°C), with high pressures being up to 5000 psig. As mentioned above, magnetite physically can be removed from the system in three different ways:

High-Pressure crystal chemistry of spinel (MgAl 2 O 4

High-pressure crystal structures and compressibilities have been determined by x-ray methods for MgAl 2 O 4 spinel and its isomorph magnetite, Fe 3 O 4. The measured bulk moduli, K, of spinel and magnetite (assuming K′=4) are 1.94±0.06 and 1.86±0.05 Mbar, respectively, in accord

Transformation of magnetite to hematite and its influence

Deformed rocks of the Itabira Iron Formation (itabirites) in Brazil show microstructural evidence of pressure solution of quartz and iron oxides; it appears that magnetite was dissolved and hematite precipitated. The dissolution of magnetite seems to be related to its transformation to hematite by oxidation of Fe 2+ to Fe 3+.

Evolution of electronic and magnetic properties of nominal

exposed to extreme conditions such as high pressure and temperature environments [3]. Iron-oxide magnetite (Fe 3O 4) is a naturally occurring, iron-rich, magnetic mineral. Nano counterparts of magnetite Journal of Physics: Condensed Matter Evolution of electronic and magnetic properties of nominal magnetite nanoparticles at high pressure probed by

AMCSD Search Results RRUFF

Equation of state of magnetite and its high-pressure modification: Thermodynamics of the Fe-O system at high pressure: Sample at P = 30.3 GPa _database_code_amcsd 0002415: 8.0636 8.0636 8.0636 90 90 90 *Fd3m.125 .125 .125: atom x y z: Fe(tet) .125 .125 .125: Fe(oct) .5 .5 .5

Effects of Advanced Amines on Magnetite Deposition of

1 day ago Furthermore, the loop system was composed of high-pressure (HP) pumps, a metering pump for injecting the Fe(II)-acetate, micro-filters for removing the remaining magnetite particles and impurities during fouling tests, various sensors (such as for pH, DO, and conductivity), a thermo-couple (T/C), preheaters, coolers, and back-pressure