Characterization of subtropical soils by mineral magnetic measurements

2000 ◽  
Vol 31 (1-2) ◽  
pp. 1-11 ◽  
Author(s):  
Shenggao Lu
2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
A. M. Espinoza-Rivas ◽  
M. A. Pérez-Guzmán ◽  
R. Ortega-Amaya ◽  
J. Santoyo-Salazar ◽  
C. D. Gutiérrez-Lazos ◽  
...  

Graphite-coated iron nanoparticles were prepared from magnetite nanoparticles by chemical vapour deposition (CVD) under methane and hydrogen atmosphere. After being purified from carbon excess, graphite-coated iron nanoparticles were tested for morphological and magnetic properties. It was found that, during the thermal process, magnetite nanoparticles 6 nm in size coalesce and transform into graphite-coated iron 200 nm in size, as revealed by scanning electron microscopy (SEM). Raman characterization assessed that high-quality graphite coats the iron core. Magnetic measurements revealed the phase change (magnetite to iron) as an increase in the saturation magnetization from 50 to 165 emu/g after the CVD process.


2002 ◽  
Vol 67 (12) ◽  
pp. 825-832 ◽  
Author(s):  
Raghu Prasad ◽  
Mala Mathur

Metal complexes of a 20-membered tetraazamacrocycle 2,12-dimethyl-3,13-di-n-propyl 1,4,11,14-tetraazacycloeicosa-1,3,11,13-tetraene(L) of the type [MLX2]X(M=Cr(III), Fe(III); X=NO3)[CoLNO3]NO3, [NiL(NO3)2], [CuL]Cl2 and [ZnLCl2]have been prepared by 2+2 cyclocondensation of 2,3-hexanedione with 1,6-diaminohexane in the presence of metal ions as templates. These complexes were characterized by elemental analyses, conductances, IR and electronic spectra and magnetic measurements.


2003 ◽  
Vol 793 ◽  
Author(s):  
Arwyn L. E. Smalley ◽  
Brandon Howe ◽  
David C. Johnson

ABSTRACTA series of cerium-containing CoSb3 samples were synthesized, with cerium quantities varying from 0 to 2 stoichiometric equivalents. These samples were annealed at low temperatures to crystallize the kinetically stable phases CexCo4Sb12 (x = 0–0.5). X-ray diffraction showed that these samples were phase pure, and Rietveld analysis on x-ray diffraction data from powder samples indicated that these samples were 25–88% crystalline. Electrical measurements showed that these samples are n-type, which was previously unknown in CexCo4Sb12. Magnetic measurements showed that the samples were paramagnetic due to the cerium being incorporated into the diamagnetic CoSb3 compound. In addition, they contained a ferromagnetic component that was attributed to the amorphous, cerium-containing phase.


2014 ◽  
Vol 1708 ◽  
Author(s):  
Nabraj Bhattarai ◽  
Subarna Khanal ◽  
Daniel Bahena ◽  
Robert L. Whetten ◽  
Miguel Jose-Yacaman

ABSTRACTThe synthesis of bimetallic magnetic nanoparticles is very challenging because of the agglomeration and non-uniform size. In this paper, we present the synthesis of monodispersed 3-5 nm sized thiolated bimetallic alloyed Au/Co nanoparticles with decahedral and icosahedral shape, their characterization using Cs-corrected scanning transmission electron microscopy (STEM) and magnetic measurements using superconducting quantum interference device (SQUID) magnetometer. The Z-contrast imaging and energy dispersive X-ray spectroscopy (EDS) mapping showed an inhomogeneous alloying with minor segregation between Au and Co at nanoscale and the SQUID measurement exhibited the ferromagnetic behavior.


2016 ◽  
Vol 94 (4) ◽  
pp. 367-372 ◽  
Author(s):  
Lana T. Huynh ◽  
Stephanie N. Bonvicini ◽  
Arthur C. Pinon ◽  
Simon Trudel

Non-stoichiometric Co2FeAl nanoparticles are formed by the in-solution thermal decomposition of the corresponding metal acetylacetonate complexes in the presence of capping ligands followed by reduction of the obtained material under an H2-containing atmosphere. Transmission electron microscopy indicates that sub-100 nm nanoparticles are obtained, with reasonable size control. Magnetic measurements indicate that the saturation magnetization, Bloch behavior, magnetization reversal, spin-wave stiffness, and exchange stiffness are all comparable to those observed for bulk and thin-film Co2FeAl, indicating that these nanomaterials are promising for use in nanoparticle-based spintronic devices.


Author(s):  
Philippe Laurent ◽  
Jean-François Fagnard ◽  
Philippe Vanderbemden

This work describes the design and realisation of an apparatus to measure simultaneously the AC magnetic properties and the temperature distribution on the top surface of bulk superconducting samples (up to 32 mm in diameter) in cryogenic conditions (temperature range 78-120 K). First the authors describe the experimental set-up used for simultaneous thermal and magnetic characterization of the sample. Next, the authors describe the practical considerations required for generating the large AC magnetic fields, possibly in the presence of DC fields. Then the authors present the data acquisition system allowing both temperature and magnetic data to be recorded at high a sampling rate.” The performances and limitations of the system are discussed.


Author(s):  
Philippe Laurent ◽  
Jean-François Fagnard ◽  
Philippe Vanderbemden

This work describes the design and realisation of an apparatus to measure simultaneously the AC magnetic properties and the temperature distribution on the top surface of bulk superconducting samples (up to 32 mm in diameter) in cryogenic conditions (temperature range 78-120 K). First the authors describe the experimental set-up used for simultaneous thermal and magnetic characterization of the sample. Next, the authors describe the practical considerations required for generating the large AC magnetic fields, possibly in the presence of DC fields. Then the authors present the data acquisition system allowing both temperature and magnetic data to be recorded at high a sampling rate." The performances and limitations of the system are discussed.


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