6.1.3.5.1 Saturation moment at 0 K

2005 ◽  
pp. 152-154
Author(s):  
R. Vautier ◽  
M. Paulus
Keyword(s):  
Saturation Moment

scholarly journals Zum paramagnetischen Verhalten von Palladium/Silber/Eisen- Legierungen/ On the Paramagnetic Behaviour of Palladium-Silver-Iron Alloys

1975 ◽  
Vol 30 (5) ◽  
pp. 645-655
Author(s):  
Peter Brill
Keyword(s):  
Electron Concentration ◽  
Magnetic Moments ◽  
Alloy Series ◽  
Band Filling ◽  
Paramagnetic Behaviour ◽  
Field Coefficient ◽  
Saturation Moment ◽  
Molecular Field Coefficient ◽  
The Moment ◽  
Curie Temperatures

Abstract The paramagnetic susceptibility of four PdAgFe alloy series containing 1, 3, 5 and 7 at. % Fe have been measured between 20° and 150 °C. On the basis of a band filling model the local moment contribution to the susceptibility has been evaluated according to a Curie -Weiss law. Assuming that the iron atoms donate 3 electrons and the silver atoms 1 electron to the Pd 4d band, the effective magnetic moments and the paramagnetic Curie temperatures of all the alloys can be represented by a single curve against the electron concentration. The effective magnetic moment is consistent with an Fe moment of 5.92 μB localized on the iron sites and a Pd moment varying with electron concentration and temperature. The same turns out to be true for the ferromagnetic region where the saturation moment, obtained on PdFe alloys and a PdAgFe alloy by different authors, is considered to arise from a localized Fe moment of 5 μB and a concentration dependent Pd moment. The molecular field coefficient for the interaction between the Fe moments and the Pd 4d electrons is found to be 850 mol/cm3 at 385 K and 1200 mol/cm3 at 0 K. Finally, the iron moment suggested in this work is contrasted with the moment derived from neutron diffraction measurements.

Investigation of Magnetic Order in Iron Oxide-Nickel Oxide Superlattices with Modulation Wavelength Less Than 80 Å

1991 ◽  
Vol 231 ◽  
Author(s):  
S. D. Berry ◽  
D. M. Lind ◽  
G. Chern ◽  
H. Mathias ◽  
L. R. Testardi
Keyword(s):  
Magnetic Order ◽  
Spontaneous Magnetization ◽  
X Ray Diffraction ◽  
High Crystalline Quality ◽  
X Ray ◽  
Long Wavelength ◽  
Saturation Moment ◽  
Very High ◽  
Modulation Wavelength

AbstractWe have investigated the magnetic order, using SQUID magnetometry, for short modulation wavelength Fe3O4/NiO superlattices, grown on single crystal MgO. Ferrimagnetic Fe3O4 has a saturation moment of ~500 emu/cm3 at 0 K and a Curie temperature of 858 K, while bulk NiO is antiferromagnetic with a NMel temperature of 525 K. Very high crystalline quality with little interdiffusion is indicated by X-ray diffraction, SEM, optical microscopy, and in-situ RHEED, and the samples show highly anisotropic electrical conductivity which also indicates the strong modulation present. Long wavelength samples (Amod > 200 Å) have a behavior only slightly different from that expected from bulk Fe3O4, but for Amod<80 Å, spontaneous magnetization is replaced by paramagnetism, with weak temperature dependence (not I/T) from 5 K to 400 K.

Saturation moment for gold in iron

1967 ◽  
Vol 25 (8) ◽  
pp. 613 ◽  
Author(s):  
M.C. Cadeville ◽  
I.A. Campbell
Keyword(s):  
Saturation Moment

scholarly journals Magnetic Properties of a Holocene Sediment Core from the Yeongsan Estuary, Southwest Korea: Implications for Diagenetic Effects and Availability as Paleoenvironmental Proxies

2021 ◽  
Vol 9 ◽  
Author(s):  
Hyeon–Seon Ahn ◽  
Jaesoo Lim ◽  
Sung Won Kim
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
South Korea ◽  
Size Distribution ◽  
Sea Level ◽  
West Coast ◽  
Magnetic Minerals ◽  
The West ◽  
Saturation Moment

The sensitivity of magnetic properties, which characterize the mineralogy, concentration, and grain size distribution of magnetic minerals, to environmental processes may provide useful information on paleoenvironmental changes in estuarine environments. Magnetic property studies of estuaries are less common than other environments and, due to the west coast of South Korea having an abundance of estuaries, it provides a good place to study these processes. In this study, we analyzed a variety of magnetic properties based on magnetic susceptibility, hysteresis parameters, progressive acquisition of isothermal remanent magnetization and first-order reversal curve data from a Holocene muddy sediment core recovered from the Yeongsan Estuary on the west coast of South Korea. We examined diagenetic effects on magnetic properties and tested their availability as proxies of paleoenvironmental change. The presence of generally low magnetic susceptibility, ubiquitous greigite-like authigenic magnetic component, and very fine magnetic particle occurrence suggested that the analyzed sediments had undergone considerable early diagenetic alteration. Electron microscopic observations of magnetic minerals support this suggestion. Our results confirm that the use of initial bulk susceptibility as a stand-alone environmental change proxy is not recommended unless it is supported by additional magnetic analyses. We recognized the existence of ferromagnetic-based variabilities related to something besides the adverse diagenetic effects, and have examined possible relationships with sea-level and major climate changes during the Holocene. The most remarkable finding of this study is the two distinct intervals with high values in magnetic coercivity (Bc), coercivity of remanence (Bcr), and ratio of remanent saturation moment to saturation moment (Mrs/Ms) that were well coincident with the respective abrupt decelerations in the rate of sea-level rise occurred at around 8.2 and 7 thousand years ago. It is then inferred that such condition with abrupt drop in sea-level rise rate would be favorable for the abrupt modification of grain size distribution toward more single-domain-like content. We modestly propose consideration of the Bc, Bcr, and Mrs/Ms variability as a potential indicator for the initiation/occurrence of sea-level stillstand/slowstand or highstand during the Holocence, at least at estuarine environments in and around the studied area.

scholarly journals Structural, Magnetic and Electronic Properties of Nanostructured Magnetic Materials

2021 ◽  
Author(s):  
◽  
Tushara Prakash
Keyword(s):  
Particle Size ◽  
Electrical Resistance ◽  
Low Temperatures ◽  
Arc Discharge ◽  
Superparamagnetic Nanoparticles ◽  
Precipitation Method ◽  
Verwey Transition ◽  
Electrostatic Charging ◽  
Saturation Moment ◽  
Co Precipitation

<p>This thesis was motivated by the different properties exhibited by magnetic nanoparticles when compared with the bulk. For example the coercivity and magnetocrystalline anisotropy vary with the particle size and the finite particle size can affect the spin-wave dispersion. When the nanoparticle radius becomes small enough it is possible to observe superparamagnetism with negligible hysteresis. The transport properties can also be different in nanoparticle composites when compared with the bulk. It is particularly interesting if the nanoparticles have a degree of electronic spin polarization because it is then possible to observe spin-dependent tunnelling. This thesis reports the results from a study of the structural, magnetic, and electronic properties of two partially electronically spin-polarized nanostructured compounds, iron-nickel alloy and magnetite, that were made using a new arc-discharge method, ion implantation and annealing, and a co-precipitation method.  It was found that permalloy powders could be made by arc-discharge where there were a range of particle sizes from nms to 10s of microns. Magnetoresistance was observed where it is due to the ordinary magnetoresistance and spin-dependent tunnelling between the particles. It was also possible to make magnetite using the arc-discharge process and the powders contained nanoparticles, large faceted nanoparticles, and larger particles in the 10s of micron range. The temperature dependence of the saturation magnetization changes at 127 K, which can be attributed to the charge-ordering Verwey transition. A large magnetoresistance was observed and attributed to spin-dependent tunnelling between the magnetite particles. It was less than predicted due to a spin-disordered interfacial region. The electrical resistance was modelled in terms of small nanoparticles coating the larger particles and electrostatic charging during tunnelling between small nanoparticles. Magnetite powders were also synthesized via a chemical co-precipitation method where nanoparticles with diameters of ~14 nm were observed. The Verwey transition was only observed in the zero-field cooled field-cooled magnetization for the arc-discharge powders. It was observed for the magnetite powders made using both methods in the temperature dependence of the saturation moment. The saturation magnetic moment for powders made using both methods has a power law dependence on temperature with an exponent of 3/2 at low temperatures and a higher value above the Verwey transition temperature 2. There was also a large magnetoresistance due to spin-dependent tunnelling for magnetite nanoparticle made using a chemical co-precipitation method and the electrical resistance could be modelled in terms of electrostatic charging during tunnelling.  NixFe₁₋x nanoparticles were made for the first time by ion beam implantation. Small superparamagnetic nanoparticles occurred after implantation. The saturation moment after implantation did not follow the Bloch’s T³/² for x=0.82, which is likely to be due to spin-waves propagating in the nanoparticle/NiyFe₁₋ySizOn matrix. A bi-modal particle size distribution of mostly spherical nanoparticles was observed for x=0.82 after annealing. An x=0.45 sample showed large asymmetric NixFe₁₋x nanoparticles with minimal smaller nanoparticles. The different nanoparticle morphologies is likely to be due to the different nucleation centres and the different initial concentration profiles. The saturation moment had an exponent of 3/2 at low temperatures and there was a contribution from surface disordered spins. A higher Ni fluence with x=0.53 lead to the formation of superparamagnetic nanoparticles that had a higher blocking temperature, indicating the formation of larger nanocrystallites. There was an enhancement in the permeability.</p>

Temperature Dependence of Pressure Effect on the Saturation Moment in Fe and Ni

1963 ◽  
Vol 18 (9) ◽  
pp. 1348-1348 ◽  
Author(s):  
Eiji Tatsumoto ◽  
Hiroshi Fujiwara ◽  
Hatsuo Tange ◽  
Takeshi Hiraoka
Keyword(s):  
Temperature Dependence ◽  
Pressure Effect ◽  
Saturation Moment

Magnetic properties of (NixCu1−x)2MnSn

1977 ◽  
Vol 55 (17) ◽  
pp. 1481-1484 ◽  
Author(s):  
R. A. MacDonald ◽  
C. V. Stager
Keyword(s):  
Magnetic Properties ◽  
Curie Temperature ◽  
Heusler Alloy ◽  
Room Temperature ◽  
Manganese Atom ◽  
Lattice Parameter ◽  
Alloy Series ◽  
Saturation Moment ◽  
Curie Temperatures

Magnetization and crystallographic measurements are reported for the Heusler alloy series (NixCu1−x)2MnSn. With the exception of Cu2MnSn and perhaps (Ni0.1Cu0.9)2MnSn all of the samples prepared had the cubic Heusler L21 structure at room temperature. The lattice parameter varies linearly as a function of composition. The saturation moment is constant at approximately 4μβ per manganese atom throughout the series. Curie temperatures vary smoothly but non-linearly with composition, providing some evidence for at least two competing mechanisms in the determination of the Curie temperature.

scholarly journals Magnetic and Martensitic Transitions in Ni2Mn1+xSn1-x Alloys

2009 ◽  
Vol 635 ◽  
pp. 97-102 ◽  
Author(s):  
Subham Chatterjee ◽  
S. Majumdar
Keyword(s):  
Ground State ◽  
Magnetic Phase ◽  
Magnetic Phase Diagram ◽  
Magnetic Interactions ◽  
Martensitic Transition ◽  
Magnetic Ground State ◽  
First Order ◽  
Saturation Moment ◽  
High Fields ◽  
Curie Temperature Tc

The magnetic phase diagram of Ni2Mn1+xSn1−x based ferromagnetic (FM) shape memory alloys for varied concentrations of x have been studied. With increasing concentration of Mn, the FM Curie temperature (TC) decreases, while the martensitic transition temperature (TM) goes higher. For x = 0.44 and 0.48, TM is close to the onset of ferromagnetism, and two distinct magnetic transitions are observed corresponding to the TC’s of the FM phases of martensite and austenite respectively. The isothermal magnetization at 5 K indicates saturating behaviour at high fields and the saturation moment drops linearly with x. The samples show reasonably large negative magnetoresistance around TM, however the magnitude drops with increasing x. The magnetoresistance is found to be highly irreversible with respect to the applied magnetic field and field induced arrested state is observed for all the FM samples studied around the first order martensitic transition. The present investigation clearly indicates complex magnetic ground state of the Ni2Mn1+xSn1−x samples with competing magnetic interactions.

Sign in / Sign up

Export Citation Format

Share Document