THE MAGNETIZATION OF A ROCK CONTAINING MAGNETITE AND HEMOILMENITE

Geophysics ◽  
1964 ◽  
Vol 29 (1) ◽  
pp. 87-92 ◽  
Author(s):  
Charles M. Carmichael
Keyword(s):  
Remanent Magnetization ◽  
Magnetic Moments ◽  
Canadian Shield ◽  
Titanium Oxides ◽  
Aeromagnetic Anomalies ◽  
X Ray ◽  
Lake Region ◽  
Unusual Occurrence

In areas such as the Canadian Shield, rocks often contain iron and titanium oxides with a remanent magnetization. These rocks can produce aeromagnetic anomalies that are positive, negative, or nonexistent depending on the magnitude and direction of the remanent component relative to that of the induced. In the Allard Lake region of Quebec there is a deposit containing up to 20 percent oxide that produces no anomaly detectable by either the airborne or ground magnetometer. Analyses of the rock by microscopic, magnetic, and X‐ray techniques have shown that it contains separate crystals of an almost pure magnetite and of exsolved hemoilmenite. The magnetite crystals are magnetized normally and the hemoilmenite crystals inversely. They are present in quantities such that their magnetic moments cancel and so produce no anomaly. While this is probably an unusual occurrence it shows that considerable care must be taken in regions where minerals having an inverse remanent magnetization may be present.

The effect of Tin additionon on Structural and magnetic properties of the stannoferrite Li0.5+0.5XFe2.5-1.5XSnXO4

2016 ◽  
Vol 12 (3) ◽  
pp. 4307-4321 ◽  
Author(s):  
Ahmed Hassan Ibrahim ◽  
Yehia Abbas
Keyword(s):  
Particle Size ◽  
Fine Particles ◽  
Magnetic Moments ◽  
Lithium Ferrite ◽  
Tem Analysis ◽  
Weiss Temperature ◽  
X Ray ◽  
Two Phases ◽  
Nanocrystalline Ferrite ◽  
20 Nm

The physical properties of ferrites are verysensitive to microstructure, which in turn critically dependson the manufacturing process.Nanocrystalline Lithium Stannoferrite system Li0.5+0.5XFe2.5-1.5XSnXO4,X= (0, 0.2, 0.4, 0.6, 0.8 and 1.0) fine particles were successfully prepared by double sintering ceramic technique at pre-sintering temperature of 500oC for 3 h andthepre-sintered material was crushed and sintered finally in air at 1000oC.The structural and microstructural evolutions of the nanophase have been studied using X-ray powder diffraction (XRD) and the Rietveld method.The refinement results showed that the nanocrystalline ferrite has a two phases of ordered and disordered phases for polymorphous lithium Stannoferrite.The particle size of as obtained samples were found to be ~20 nm through TEM that increases up to ~ 85 nmand isdependent on the annealing temperature. TEM micrograph reveals that the grains of sample are spherical in shape. (TEM) analysis confirmed the X-ray results.The particle size of stannic substituted lithium ferrite fine particle obtained from the XRD using Scherrer equation.Magneticmeasurements obtained from lake shore’s vibrating sample magnetometer (VSM), saturation magnetization ofordered LiFe5O8 was found to be (57.829 emu/g) which was lower than disordered LiFe5O8(62.848 emu/g).Theinterplay between superexchange interactions of Fe3+ ions at A and B sublattices gives rise to ferrimagnetic ordering of magnetic moments,with a high Curie-Weiss temperature (TCW ~ 900 K).

scholarly journals Revealing noncollinear magnetic ordering at the atomic scale via XMCD

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fridtjof Kielgast ◽  
Ivan Baev ◽  
Torben Beeck ◽  
Federico Pressacco ◽  
Michael Martins
Keyword(s):  
Ground State ◽  
Magnetic Circular Dichroism ◽  
Magnetic Moments ◽  
Magnetic Ordering ◽  
Atomic Scale ◽  
Angle Of Incidence ◽  
X Ray ◽  
First Time ◽  
X Ray Absorption ◽  
Magnetic Sublattices

AbstractMass-selected V and Fe monomers, as well as the heterodimer $${\text{Fe}}_1{\text{V}}_1$$ Fe 1 V 1 , were deposited on a Cu(001) surface. Their electronic and magnetic properties were investigated via X-ray absorption (XAS) and X-ray magnetic circular dichroism (XMCD) spectroscopy. Anisotropies in the magnetic moments of the deposited species could be examined by means of angle resolving XMCD, i.e. changing the X-ray angle of incidence. A weak adatom-substrate-coupling was found for both elements and, using group theoretical arguments, the ground state symmetries of the adatoms were determined. For the dimer, a switching from antiparallel to parallel orientation of the respective magnetic moments was observed. We show that this is due to the existence of a noncollinear spin-flop phase in the deposited dimers, which could be observed for the first time in such a small system. Making use of the two magnetic sublattices model, we were able to find the relative orientations for the dimer magnetic moments for different incidence angles.

MAGNETIC MICROSPECTROSCOPY BY A COMBINATION OF XMCD AND PEEM

2002 ◽  
Vol 09 (02) ◽  
pp. 877-881 ◽  
Author(s):  
S. IMADA ◽  
S. SUGA ◽  
W. KUCH ◽  
J. KIRSCHNER
Keyword(s):  
Circular Dichroism ◽  
Full Advantage ◽  
Quantitative Evaluation ◽  
Magnetic Circular Dichroism ◽  
Magnetic Moments ◽  
Magnetic Domain ◽  
X Ray ◽  
Circular Dichroïsm

The benefits of combining soft X-ray magnetic circular dichroism and photoelectron microscopy are demonstrated by applying this combination (XMCD–PEEM) not only to magnetic domain imaging but also to quantitative evaluation of the distribution of spin and orbital magnetic moments. The latter takes full advantage of the spectroscopic aspect of XMCD–PEEM.

scholarly journals Синтез, структура и магнитные свойства многослойных наногетероструктур Fe|MgO|Cr|MgO|Fe

2021 ◽  
Vol 63 (9) ◽  
pp. 1306
Author(s):  
Е.М. Якунина ◽  
Е.А. Кравцов ◽  
Yu.N. Khaydukov ◽  
Н.О. Антропов ◽  
В.В. Проглядо
Keyword(s):  
Magnetic Properties ◽  
High Resolution ◽  
Exchange Interaction ◽  
Magnetic Moments ◽  
Ferromagnetic Material ◽  
Structural Studies ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Metal Layers

Layered nanoheterostructures Fe | MgO | Cr | MgO | Fe is an artificial ferromagnetic material in which the exchange interaction of the magnetic moments of Fe layers through intermediate dielectric and metal layers can lead to magnetic configurations that are not realized in the well-studied Fe | MgO | Fe and Fe | Cr | Fe. In this work, we investigated the correlations of the structural and magnetic properties of layered nanoheterostructures Fe (10 nm) | MgO (1.5 nm) | Cr (t nm) | MgO (1.5 nm) | Fe (7 nm) (thickness t = 0.9 and 1.8 nm). Structural studies performed using X-ray diffractometry and high-resolution reflectometry confirmed the formation of a textured structure and revealed its well-defined layered character with sharp interlayer boundaries.

scholarly journals Detecting quadrupole: a hidden source of magnetic anisotropy for Manganese alloys

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun Okabayashi ◽  
Yoshio Miura ◽  
Yohei Kota ◽  
Kazuya Z. Suzuki ◽  
Akimasa Sakuma ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Quantum Physics ◽  
Theoretical Calculations ◽  
Magnetic Moments ◽  
Perpendicular Magnetic Anisotropy ◽  
Linear Dichroism ◽  
First Principles Calculation ◽  
X Ray ◽  
Manganese Alloys ◽  
Ordered Alloys

Abstract Mn-based alloys exhibit unique properties in the spintronics materials possessing perpendicular magnetic anisotropy (PMA) beyond the Fe and Co-based alloys. It is desired to figure out the quantum physics of PMA inherent to Mn-based alloys, which have never been reported. Here, the origin of PMA in ferrimagnetic Mn3− δ Ga ordered alloys is investigated to resolve antiparallel-coupled Mn sites using x-ray magnetic circular and linear dichroism (XMCD/XMLD) and a first-principles calculation. We found that the contribution of orbital magnetic moments in PMA is small from XMCD and that the finite quadrupole-like orbital distortion through spin-flipped electron hopping is dominant from XMLD and theoretical calculations. These findings suggest that the spin-flipped orbital quadrupole formations originate from the PMA in Mn3− δ Ga and bring the paradigm shift in the researches of PMA materials using x-ray magnetic spectroscopies.

scholarly journals Microstructure, Microhardness, and Wear Properties of Cobalt Alloy Electrodes Coated with TiO2 Nanoparticles

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1186
Author(s):  
Sebastian Balos ◽  
Petar Janjatovic ◽  
Miroslav Dramicanin ◽  
Danka Labus Zlatanovic ◽  
Branka Pilic ◽  
...  
Keyword(s):  
Modified Electrodes ◽  
Wear Testing ◽  
Titanium Oxides ◽  
Cobalt Alloy ◽  
Wear Properties ◽  
X Ray ◽  
Eds Analysis ◽  
Present Complex ◽  
Complex Carbides ◽  
Pin On Disc

In this paper, the influence of TiO2 nanoparticle coating on cobalt-based electrodes was studied. Different coating treatment times were applied, and the results were compared to the hard-faced layer obtained with unmodified electrodes. The hard facing was done in three layers, the first being a Ni-based interlayer, followed by two layers of corrosion and wear-resistant Co-based Stellite 6 alloy. Pin-on-disc wear testing was applied, along with the metallographic study and hardness measurements of the hard-faced layers. Furthermore, energy-dispersive X-ray spectroscopy (EDS) analysis was conducted. It was found that the microstructural properties, as well as microhardness profiles, are modified in hard-faced layers obtained with modified electrodes. Interdendritic distances are altered, as are the dendrite growth directions. Titanium oxides are formed, which, along with the present complex carbides, increase the wear resistance of the hard-faced layers compared to layers obtained with untreated electrodes.

Heterobimetallische 3d-4f-Komplexe mit Bis(1,2-dithiooxalato)nickelat(II) als planarem Brückenbaustein / Heterobimetallic 3d-4f-Complexes with Bis(1,2-dithiooxalato)nickelate(II) as Planar Bridging Block

2005 ◽  
Vol 60 (11) ◽  
pp. 1149-1157 ◽  
Author(s):  
Matthias Siebold ◽  
Alexandra Kelling ◽  
Uwe Schilde ◽  
Peter Strauch
Keyword(s):  
Room Temperature ◽  
Magnetic Moments ◽  
Lanthanide Ions ◽  
Water Molecules ◽  
Unit Cell Parameters ◽  
Ionic Radii ◽  
X Ray ◽  
Cell Parameters ◽  
Heterobimetallic Complexes ◽  
The Individual

Planar bis(1,2-dithiooxalato)nickelates(II) react in aqueous solutions of lanthanide ions to form pentanuclear, heterobimetallic complexes of the general composition [{Ln(H2O)n}2- {Ni(dto)2}3]・xH2O (Ln = Y3+, La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+; n = 4 or 5; x = 9 - 12). With [{Nd(H2O)5}2{Ni(S2C2O2)2}3]・xH2O (x = 10 - 12) (1) and [{Er(H2O)4}2{Ni(S2C2O2)2}3]・xH2O (x = 9 - 10) (2) we were able to isolate two complexes of this series as single crystals, which were characterized by X-ray structure analysis. Depending on the individual ionic radii of the lanthanide ions, the compounds crystallize in two different crystal systems with the following unit cell parameters: 1, monoclinic in P21/c with a = 11.3987(13), b = 11.4878(8), c = 20.823(2) Å , β = 98.907(9)° and Z = 2; 2, triclinic in P1̅ with a = 10.5091(6), b = 11.0604(6), c = 11.2823(6) Å , α = 107.899(4)°, β = 91.436(4)°, γ = 112.918(4)° and Z = 1. The channels and cavities appearing in the packing of the molecules are occupied by uncoordinated water molecules. High magnetic moments up to 14.65 BM./f.u. have been observed at room temperature due to the combined moments of the individual lanthanide ions.

Quaternary intermetallics RE2Pt3Ga4In (RE=Y, Gd-Tm) – intergrowth structures of NdRh2Sn4 and TiNiSi related slabs

2020 ◽  
Vol 235 (4-5) ◽  
pp. 117-125
Author(s):  
Myroslava Horiacha ◽  
Maximilian K. Reimann ◽  
Jutta Kösters ◽  
Vasyl‘ I. Zaremba ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystals ◽  
High Frequency ◽  
Magnetic Moments ◽  
Intermetallic Phases ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Arc Melting ◽  
Intergrowth Structures ◽  
A Site

AbstractThe quaternary gallium-rich intermetallic phases RE2Pt3Ga4In with RE = Y and Gd-Tm were synthesized by arc-melting of the elements and subsequent annealing. Small single crystals were obtained by high-frequency annealing of the samples in sealed tantalum ampoules. The polycrystalline samples were characterized through their X-ray powder patterns. The RE2Pt3Ga4In phases crystallize with a site ordering variant of the orthorhombic Y2Rh3Sn5 type, space group Cmc 21. The structures of Gd2Pt3Ga4In, Dy2Pt3Ga4.14In0.86, Er2Pt3Ga4.17In0.83 and Tm2Pt3Ga4.21In0.79 were refined from single-crystal X-ray diffraction data. The single crystals reveal small homogeneity ranges RE2Pt3Ga4±xIn1±x. The striking geometrical structural building units are slightly distorted trigonal prisms around the three crystallographically independent platinum atoms: Pt1@RE4Ga2, Pt2@RE2Ga4 and Pt3@RE2Ga2In2. Based on these prismatic building units, the RE2Pt3Ga4In structures can be described as intergrowth variants of TiNiSi and NdRh2Sn4 related structural slabs. Temperature dependent magnetic susceptibility studies of Gd2Pt3Ga4In and Tb2Pt3Ga4In show Curie-Weiss behavior and the experimental magnetic moments confirm stable trivalent gadolinium respectively terbium. Gd2Pt3Ga4In and Tb2Pt3Ga4In order antiferromagnetically at TN = 15.8(1) and 26.0(1) K. Magnetization curves at 3 K show field-induced spin reorientations.

First principles calculations of intersite disorder influence on the electronic structure and X-ray magnetic circular dichroism in CoFeMnSi Heusler alloy

2020 ◽  
Vol 31 (08) ◽  
pp. 2050109
Author(s):  
S. Uba ◽  
A. Bonda ◽  
L. Uba ◽  
L. V. Bekenov ◽  
V. N. Antonov
Keyword(s):  
Electronic Structure ◽  
Circular Dichroism ◽  
First Principles ◽  
Heusler Alloy ◽  
Magnetic Circular Dichroism ◽  
Magnetic Moments ◽  
X Ray ◽  
The Rich ◽  
X Ray Absorption ◽  
Circular Dichroïsm

Electronic structure, X-ray absorption, and magnetic circular dichroism (XMCD) spectra in the CoFeMnSi Heusler alloy were studied from first principles. Fully relativistic Dirac linear muffin-tin orbital band structure method was implemented with various exchange–correlation functionals tested. The supercell approach was used to study the influence of intersite disorder, at the levels of 6.25%, 12.5%, and 25% within transition metal sites, on the XMCD spectra at [Formula: see text] edges and spin polarization (SP) at the Fermi level. It is found that most sensitive to Fe–Mn and Co–Fe disorder are XMCD spectra at [Formula: see text] edges of Fe, while the sensitivity decreases from Mn to Co. It is shown that magnetic moments estimated with the use of magneto-optical (MO) sum rules agree with the ab initio calculated ones to within [Formula: see text], [Formula: see text], and [Formula: see text], for Co, Fe, and Mn, respectively. The calculated SP decreases from 99% for ordered CoFeMnSi alloy, to 96% upon 25% Co–Fe disorder, to 83% for Fe–Mn disorder, and to 42% in the case of Co–Mn disorder. The calculated spectra agree well with the available experimental data. The rich XMCD spectral structures are predicted from first principles at Fe, Co, Mn and Si [Formula: see text] edges.

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