MAGNETIC BEHAVIOR OF U(TxAl1-x)2 COMPOUNDS (T=Co, Ni, Mn)

2006 ◽  
Vol 20 (26) ◽  
pp. 1677-1683
Author(s):  
P. LUCACI ◽  
E. CULEA
Keyword(s):  
Magnetic Fields ◽  
Magnetic Measurements ◽  
Magnetic Moments ◽  
Magnetic Behavior ◽  
Absolute Magnitude ◽  
Structural Data ◽  
Spin Fluctuations ◽  
Magnetic Parameters ◽  
Uranium Ion ◽  
Curie Temperatures

Magnetic behavior and structural data of the U(T x Al 1-x)2 compounds, where T = Co, Ni and Mn , were reported. Magnetic measurements were performed in the temperature range 4.2–800 K and magnetic fields up to 7 T. The gradual replacement of Al by Co , Ni and Mn ions leads to the decrease of the effective magnetic moments per uranium ion, and of the paramagnetic Curie temperatures in absolute magnitude. This composition evolution of the two magnetic parameters of the U(T x Al 1-x)2 compounds suggests a gradual suppression of the spin fluctuations with replacing the Al ions by T ions.

MAGNETIC BEHAVIOR OF Al2GdNi COMPOUND

2006 ◽  
Vol 20 (08) ◽  
pp. 401-408 ◽  
Author(s):  
M. COLDEA ◽  
V. POP ◽  
L. G. PASCUT ◽  
D. TODORAN ◽  
R. PACURARIU
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Magnetic Fields ◽  
Exchange Interaction ◽  
Magnetic Moment ◽  
Magnetic Measurements ◽  
Spontaneous Magnetization ◽  
Magnetic Behavior ◽  
Spin Fluctuations ◽  
Local Exchange

The magnetic properties of Al 2 GdNi compound have been investigated using magnetic measurements in the temperature range 4.2–300 K and with magnetic fields of up to 9 T. Al 2 GdNi orders ferromagnetically at Tc = 36.7 K with a magnetic moment of 7.25 μB/ f.u. , obtained from the spontaneous magnetization extrapolated to 0 K. The magnetic susceptibility obeys the Curie–Weiss law with μ eff = 8.6 μB/ f.u. and θp = 26.8 K . The results are discussed in terms of the Ruderman–Kittel–Kasuya–Yosida theory, the polarization of 5d electrons by the local exchange interaction 4f-5d and the spin fluctuations on Ni sites.

scholarly journals Reducing the influence of interference of spacecraft magnetic field on magnetic measurements

2019 ◽  
Vol 18 (2) ◽  
pp. 33-40
Author(s):  
A. M. Beznyakov ◽  
I. S. Guriev ◽  
I. P. Ryzhova
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Support Systems ◽  
Magnetic Measurements ◽  
Magnetic Moments ◽  
Navigation Support

The article presents constructive ways of reducing the influence of magnetic interference from spacecraft, due to its own magnetic fields, on the on-board magnetic measurements, as well as reducing the resulting magnetic moments. Well-known methods of removing magnetometer sensors from the locations of the most powerful sources of magnetic fields of a spacecraft, in particular, using extendable booms, are considered. In addition, methods for reducing the influence of spacecraft self- magnetic fields on the onboard magnetometric navigation support systems using known closed and proposed hemispherical ferromagnetic shields are considered

Magnetic Properties of the U1-xYxNiAl System

2003 ◽  
Vol 17 (22) ◽  
pp. 1181-1185 ◽  
Author(s):  
P. Lucaci ◽  
Ileana Lupsa
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
Effective Magnetic Moment ◽  
Uranium Atom ◽  
Absolute Magnitude ◽  
Spin Fluctuations ◽  
Temperature Range ◽  
Yttrium Content ◽  
Curie Temperatures

The magnetic properties of the U 1-x Y x NiAl system were studied in the 4–600 K temperature range fields up to 7 T. The systems with x≤0.8 were analyzed in terms of the spin fluctuations theory. The system presents a Curie–Weiss type behavior over a certain temperature T*. The paramagnetic Curie temperatures are negative and decrease in absolute magnitude as yttrium content increases. The effective magnetic moment per uranium atom is composition independent (≈3.1 μB) proving the presence of temperature induced spin fluctuations.

scholarly journals A Variety of Magnetism in CuMpt6 (M=3d Transition Metals) Ternary Alloys

1970 ◽  
Vol 32 (2) ◽  
Author(s):  
AK Das ◽  
AKM Zakaria ◽  
I Kamal
Keyword(s):  
Spin Glass ◽  
Quantum Interference ◽  
Magnetic Moments ◽  
Magnetic Behavior ◽  
Ternary Alloys ◽  
Ferromagnetic Behavior ◽  
Ferromagnetic Interaction ◽  
Glass Type ◽  
Academy Of Sciences ◽  
Curie Temperatures

The magnetic properties of polycrystalline CuMPt6 (M= Ti, V, Cr, Mn, Fe, Co and Ni) ternary alloys were studied by Superconducting Quantum Interference Device (SQUID) over the temperature range 4-300 K. Magnetization measurements revealed that the compounds containing M=Ti, V and Ni are paramagnetic. A spin glass type magnetic behavior appeared in the compounds with M= Cr and Mn in their annealed state and the corresponding temperatures for freezing the magnetic moments were Tg= 15 and 40 K, respectively. Positive values of the paramagnetic Curie temperature (Q) indicated that the ferromagnetic interaction is dominant in these spin-glass compounds. The compounds with M= Fe and Co showed ferromagnetic behavior having Curie temperatures (TC) = 230, and 190 K, respectively. Hysteresis study showed that the alloy with M=Co was magnetically softer than that with M=Fe. Keywords: CuMPt6 ternary alloys, Magnetic behavior, Effective magnetic moments (Peff), Spin glass type. doi: 10.3329/jbas.v32i2.2428 Journal of Bangladesh Academy of Sciences Vol.32(2) 2008 218-225

MAGNETIC PROPERTIES OF THE (DyxU1-x)2AlCo3 SYSTEM

2006 ◽  
Vol 20 (21) ◽  
pp. 1343-1349
Author(s):  
ILEANA LUPSA
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
High Temperature ◽  
Field Dependence ◽  
Magnetic Field Dependence ◽  
Magnetic Moments ◽  
Spin Fluctuations ◽  
Paramagnetic Behavior ◽  
Curie Temperatures ◽  
Paramagnetic Properties

The magnetic properties of the Dy x U 1-x AlCo 3 system, investigated in the 4–800 K temperature range and fields up to 80 kOe indicated ferrimagnetic order for x≥0.2. The cobalt magnetic moments opposite to dysprosium and the Curie temperatures decrease with decreasing Dy content. The internal magnetic field dependence of the Co moment shows that cobalt moment becomes saturated above 1000 kOe. The high temperature paramagnetic behavior follows a Curie–Weiss type law evidencing effective magnetic moments on Co positions. The paramagnetic properties are analyzed in the spin fluctuations model.

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.

Magnetic ordering in relaxor ferroelectric (1 − x)Pb(Fe2/3W1/3)O3–xPbTiO3 single crystals

2007 ◽  
Vol 22 (8) ◽  
pp. 2116-2124 ◽  
Author(s):  
Li Feng ◽  
Haiyan Guo ◽  
Zuo-Guang Ye
Keyword(s):  
Single Crystals ◽  
Magnetic Measurements ◽  
Ferroelectric Properties ◽  
Magnetic Ordering ◽  
Magnetic Behavior ◽  
Relaxor Ferroelectric ◽  
X Ray Diffraction ◽  
Ferroelectric State ◽  
Temperature Changes ◽  
Temperature Solution

Single crystals of the perovskite solid solution (1 − x)Pb(Fe2/3W1/3)O3–xPbTiO3, with x = 0, 0.07, 0.27, and 0.75, have been synthesized by the high-temperature solution growth using PbO as flux and characterized by x-ray diffraction and dielectric and magnetic measurements. The crystal structure at room temperature changes from a pseudocubic to a tetragonal phase with the PbTiO3 (PT) content increasing to x ⩾ 0.27. As the amount of PT increases, the relaxor ferroelectric behavior of Pb(Fe2/3W1/3)O3 (PFW) is transformed toward a normal ferroelectric state with sharp and nondispersive peaks of dielectric permittivity at TC. Two types of magnetic orderings are observed on the temperature dependence of the magnetization in the crystals with x ⩽ 0.27. This behavior is explained based on the relationships among the magnetic ordering, perovskite structure, composition, and relaxor ferroelectric properties. Furthermore, the macroscopic magnetization of the system was measured under the application of a magnetic field, which demonstrates different magnetic behavior associated with the weakly ferromagnetic, antiferromagnetic, and paramagnetic ordering in the temperature range of 2 to 390 K. Interestingly, the low-temperature ferromagnetism is enhanced by the addition of ferroelectric PT up to x = 0.27.

High-pressure / High-temperature Studies on the Stannides RENiSn (RE = Ce, Pr, Nd, Sm) and REPdSn (RE = La, Pr, Nd)

2008 ◽  
Vol 63 (6) ◽  
pp. 695-706 ◽  
Author(s):  
Jan F. Riecken ◽  
Gunter Heymann ◽  
Wilfried Hermes ◽  
Ute Ch. Rodewald ◽  
Rolf-Dieter Hoffmann ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Magnetic Moments ◽  
Structural Data ◽  
Normal Pressure ◽  
Space Group ◽  
Type Space ◽  
High Pressure Phase Transition ◽  
High Pressure High Temperature ◽  
Rare Earth Coordination

The normal-pressure (NP) orthorhombic TiNiSi-type (space group Pnma) stannides RENiSn (RE = Ce, Pr, Nd, Sm) and REPdSn (RE = La, Pr, Nd) were transformed into the corresponding hexagonal ZrNiAl-type (space group P6̄2m) high-pressure (HP) modifications under multianvil high-pressure (7.5 - 11.5 GPa) high-temperature (1100 - 1200 °C) conditions. The structures of NP-CeNiSn, HPPrNiSn, NP-NdNiSn, HP-LaPdSn, HP-PrPdSn, and HP-NdPdSn were refined from single crystal X-ray diffractometer data. Structural data for HP-SmNiSn were obtained from a Rietveld powder refinement. The high-pressure phase transition significantly changes the rare earth coordination, i. e. 4 RE + 6 Ni(Pd) + 6 Sn atoms for the NP-phases and 6 RE + 5 Ni(Pd) + 6 Sn atoms for the HPphases. Susceptibility measurements of HP-PrPdSn and HP-NdPdSn reveal paramagnetic behavior with experimental magnetic moments of 3.61(1) μB/Pr atom and 3.66(1) μB/Nd atom, respectively. Low-temperature susceptibility and specific heat data point to inhomogeneous magnetism and spinglass behavior, respectively.

Quenching of spin fluctuations by high magnetic fields

1991 ◽  
Vol 100 (1-3) ◽  
pp. 292-321 ◽  
Author(s):  
K. Ikeda ◽  
S.K. Dhar ◽  
M. Yoshizawa ◽  
K.A. Gschneidner
Keyword(s):  
Magnetic Fields ◽  
Spin Fluctuations ◽  
High Magnetic Fields
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