Magnetic Clusters in Natural Ferro-Chromian Spinels

2015 ◽  
Vol 233-234 ◽  
pp. 587-590
Author(s):  
Tatyana Sherendo ◽  
Valentin Mitrofanov ◽  
Aleksey Vdovin ◽  
Petr Martyshko ◽  
Aleksey Alexeev ◽  
...  
Keyword(s):  
Magnetic Force ◽  
Chrome Spinel ◽  
Middle Urals ◽  
Magnetic Clusters ◽  
Magnetic Dipoles ◽  
Force Microscopy ◽  
Geological Processes ◽  
Or Groups ◽  
Natural Iron ◽  
Iron Chromium

The results of investigations of natural iron-chromium spinels of variable composition Fe2+(Cr2-xFex3+)O4 of the chromite-bearing Klyuchevskoi massif (Middle Urals), which are the main carriers of the magnetization of rocks are presented. Substantial changes in the composition and in magnetic structure of accessory chrome-spinels scattered in the host rock are established, unlike the almost unaltered ore-forming chrome-spinels, under the influence of secondary geological processes. To establish the connection between the chrome-spinel changes at the microlevel and features of the geomagnetic field anomalies created by this carrier of magnetization of rocks, it is carried out a complex of investigations of Fe-Cr-spinels (thermomagnetic analysis over the temperature range (4÷1000) K; magnetic resonance (MR) spectroscopy and magnetic force microscopy (MFM) in addition to magnetomineralogical studies). As a result, in the relict areas of grains of the accessory chrome-spinels were first discovered the magnetic clusters (superparamagnetic phases) in the form of single or groups of 2 – 3 magnetic dipoles of tens nanometers in size, or in the form of chain-like structures of magnetic dipoles/single domains.

scholarly journals Composition, structure and magnetic properties of ore chrome spinels of the Klyuchevsky massif (Middle Urals)

2020 ◽  
Vol 1 (1) ◽  
pp. 73-85
Author(s):  
Aleksandr Valer’evich ALEKSEEV ◽  
◽  
Tat’yana Andreevna SHERENDO ◽  
Keyword(s):  
Magnetic Properties ◽  
Field Test ◽  
Magnetic Phase ◽  
Test Site ◽  
Chrome Spinel ◽  
Middle Urals ◽  
Geophysical Field ◽  
Magnetic Dipoles ◽  
Geomagnetic Fields ◽  
Composition Structure

The overall objective was to create a geological and geophysical field test site for chromite mineralization and detailed works in order to determine and test the main search criteria for disseminated mineralization. To create a field test site, an area was selected in the southern part of the Klyuchevsky massif characterized by abundant development of disseminated mineralization in the banded dunite-clinopyroxenite complex and strong processes of superimposed metamorphism. This paper gives a piece of research on the composition of chrome spinel from disseminated ores that underwent metamorphism of different stages. The composition of chrome spinelide, the evolution of its metamorphism and the related changes in its magnetic properties are examined in detail. It was established that all chrome spinels are of a high-chromium type, to one degree or another, they were subject to secondary changes, leading to the appearance of magnetic phases. The degree and nature of the change in chrome spinels in dunites directly depends on the degree of metamorphism of the rocks. The formation of the magnetic phase begins with the formation of nuclei consisting of single magnetic dipoles, groups of 2-3 dipoles or chains of magnetic dipoles, which was first discovered by us in chrome spinel grains. Then there is an increase in the number of such phases, the appearance of optically diagnosed secondary changes in chrome spinelide. A comparison of the degree of variation of chrome spinel and its reflection in the pattern of recorded anomalies of geomagnetic fields allows us to identify some criteria for the search for disseminated chromite ores of this type.

Study of MFM Application in Semiconductor Failure Analysis

2004 ◽  
Author(s):  
Way-Jam Chen ◽  
Lily Shiau ◽  
Ming-Ching Huang ◽  
Chia-Hsing Chao
Keyword(s):  
Magnetic Field ◽  
Failure Analysis ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Current Flow ◽  
Force Microscopy ◽  
The Magnetic Field ◽  
A Current

Abstract In this study we have investigated the magnetic field associated with a current flowing in a circuit using Magnetic Force Microscopy (MFM). The technique is able to identify the magnetic field associated with a current flow and has potential for failure analysis.

scholarly journals Magnetic Force Microscopy: Comparison and Validation of Different Magnetic Force Microscopy Calibration Schemes (Small 11/2020)

Small ◽  
2020 ◽  
Vol 16 (11) ◽  
pp. 2070058
Author(s):  
Héctor Corte‐León ◽  
Volker Neu ◽  
Alessandra Manzin ◽  
Craig Barton ◽  
Yuanjun Tang ◽  
...  
Keyword(s):  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Force Microscopy

Magnetic Domain Observation on Melt-Spun Nd-Fe-B Ribbons Using Magnetic Force Microscopy

1999 ◽  
Vol 577 ◽  
Author(s):  
A. Gavrin ◽  
C. Sellers ◽  
S.H. Liouw
Keyword(s):  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Magnetic Measurements ◽  
Magnetic Domain ◽  
Domain Size ◽  
High Coercivity ◽  
Uniform Domain ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Melt Spun

ABSTRACTWe have used Magnetic Force Microscopy (MFM) to study the magnetic domain structures of melt-spun Nd-Fe-B ribbons. The ribbons are commercial products (Magnequench International, Inc. MQP-B and MQP-B+) with a thickness of approximately 20 microns. These materials have identical composition, Nd12.18B5.36Fe76.99Co5.46, but differ in quenching conditions. In order to study the distribution of domain sizes through the ribbon thickness, we have prepared cross-sectional samples in epoxy mounts. In order to avoid artifacts due to tip-sample interactions, we have used high coercivity CoPt coated MFM tips. Our studies show domain sizes typically ranging from 50-200 nm in diameter. This is in agreement with studies of similar materials in which domains were investigated in the plane of the ribbon. We also find that these products differ substantially in mean domain size and in the uniformity of the domain sizes as measured across the ribbon. While the B+ material shows nearly uniform domain sizes throughout the cross section, the B material shows considerably larger domains on one surface, followed by a region in which the domains are smaller than average. This structure is presumably due to the differing quench conditions. The region of coarse domains varies in thickness, disappearing in some areas, and reaching a maximum thickness of 2.75 µm in others. We also describe bulk magnetic measurements, and suggest that.

scholarly journals Magnetic Driven Two-Finger Micro-Hand with Soft Magnetic End-Effector for Force-Controlled Stable Manipulation in Microscale

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 410
Author(s):  
Dan Liu ◽  
Xiaoming Liu ◽  
Pengyun Li ◽  
Xiaoqing Tang ◽  
Masaru Kojima ◽  
...  
Keyword(s):  
Magnetic Force ◽  
Force Feedback ◽  
Soft Magnetic ◽  
End Effector ◽  
Force Microscopy ◽  
System A ◽  
Atomic Force ◽  
Afm Probe ◽  
End Effectors ◽  
Fixed End

In recent years, micromanipulators have provided the ability to interact with micro-objects in industrial and biomedical fields. However, traditional manipulators still encounter challenges in gaining the force feedback at the micro-scale. In this paper, we present a micronewton force-controlled two-finger microhand with a soft magnetic end-effector for stable grasping. In this system, a homemade electromagnet was used as the driving device to execute micro-objects manipulation. There were two soft end-effectors with diameters of 300 μm. One was a fixed end-effector that was only made of hydrogel, and the other one was a magnetic end-effector that contained a uniform mixture of polydimethylsiloxane (PDMS) and paramagnetic particles. The magnetic force on the soft magnetic end-effector was calibrated using an atomic force microscopy (AFM) probe. The performance tests demonstrated that the magnetically driven soft microhand had a grasping range of 0–260 μm, which allowed a clamping force with a resolution of 0.48 μN. The stable grasping capability of the magnetically driven soft microhand was validated by grasping different sized microbeads, transport under different velocities, and assembly of microbeads. The proposed system enables force-controlled manipulation, and we believe it has great potential in biological and industrial micromanipulation.

scholarly journals Observation of interacting Josephson vortex chains by magnetic force microscopy

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Sergey Yu. Grebenchuk ◽  
Razmik A. Hovhannisyan ◽  
Viacheslav V. Dremov ◽  
Andrey G. Shishkin ◽  
Vladimir I. Chichkov ◽  
...  
Keyword(s):  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Josephson Vortex ◽  
Force Microscopy

A comparison of domain images obtained for nanophase alloys by magnetic force microscopy and high resolution Lorentz electron microscopy

1995 ◽  
Vol 31 (6) ◽  
pp. 3349-3351 ◽  
Author(s):  
M.R.J. Gibbs ◽  
M.A. Al-Khafaji ◽  
W.M. Rainforth ◽  
H.A. Davies ◽  
K. Babcock ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Force Microscopy

Fabrication of Magnetic Tips for High-Resolution Magnetic Force Microscopy

2013 ◽  
Vol 543 ◽  
pp. 35-38 ◽  
Author(s):  
Masaaki Futamoto ◽  
Tatsuya Hagami ◽  
Shinji Ishihara ◽  
Kazuki Soneta ◽  
Mitsuru Ohtake
Keyword(s):  
Magnetic Material ◽  
High Resolution ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Magnetic Force Microscope ◽  
Force Microscopy ◽  
High Magnetic Moment ◽  
Tip Radius ◽  
Better Than ◽  
Sputtering System

Effects of magnetic material, coating thickness, and tip radius on magnetic force microscope (MFM) spatial resolution have been systematically investigated. MFM tips are prepared by using an UHV sputtering system by coating magnetic materials on non-magnetic Si tips employing targets of Ni, Ni-Fe, Co, Fe, Fe-B, and Fe-Pd. MFM spatial resolutions better than 9 nm have been confirmed by employing magnetic tips coated with high magnetic moment materials with optimized thicknesses.

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