Field Dependent Susceptibility and Localized Spin Fluctuations in PdRhNi Alloys

1975 ◽  
Vol 53 (2) ◽  
pp. 145-150 ◽  
Author(s):  
R. W. Cochrane ◽  
F. T. Hedgcock ◽  
J. P. Tidman ◽  
M. J. Zuckermann
Keyword(s):  
Low Temperature ◽  
Magnetic Fields ◽  
Concentration Dependence ◽  
Spin Fluctuation ◽  
Spin Fluctuations ◽  
Magnetization Measurements ◽  
Scaling Parameter ◽  
Local Spin ◽  
Field Dependent

Low temperature magnetization measurements in magnetic fields up to 55 kOe are reported for a series of PdRhNi alloys containing 1 to 7 at.% Rh and up to 1 at.% Ni. These data indicate a critical Ni concentration for ferromagnetism close to 2 at.%. Comparison of the field and concentration dependence of the susceptibility to the magnetoresistance data of Purwins et al. reveals that the coefficient of the T2 local spin fluctuation resistivity scales directly with the nickel susceptibility. Experimentally, the scaling parameter varies only slightly with Rh concentration, a result which extends to the binary PdNi alloys.

Low-Temperature Spin Fluctuations beyond Spin Waves

2015 ◽  
Vol 233-234 ◽  
pp. 20-24 ◽  
Author(s):  
N.B. Melnikov ◽  
B.I. Reser
Keyword(s):  
Low Temperature ◽  
Spin Fluctuation ◽  
Functional Integral ◽  
Spin Fluctuations ◽  
Integral Formalism ◽  
Ferromagnetic Metals ◽  
Wave Approximation ◽  
Dynamic Spin ◽  
Functional Integral Formalism ◽  
Temperature Dynamic

A simple low-temperature dynamic spin-fluctuation theory of ferromagnetic metals is developed. The theory is based on the functional integral formalism for the multiband Hubbard Hamiltonian and takes into account both single-site and nonlocal spin fluctuations. We show that our approach correctly reproduces the T3/2 law at low temperatures. The calculated results of magnetic properties for Fe and Fe0.65Ni0.35 Invar demonstrate that the approach works on a much wider temperature interval than the spin-wave approximation.

scholarly journals The Thermopower and Resistivity of Nearly Magnetic Dilute Alloys

2021 ◽  
Author(s):  
◽  
Constantin Wassilieff
Keyword(s):  
Low Temperature ◽  
Spin Fluctuation ◽  
Residual Resistivity ◽  
Spin Fluctuations ◽  
Magnetic Alloy ◽  
Drag Effect ◽  
Glass Substrates ◽  
Dilute Alloys ◽  
Fluctuation Temperature ◽  
Impurity Sites

<p>In some nearly magnetic dilute alloys, in which the host and impurity are transition metals of similar electronic structure, the thermopower is observed to form a "giant" peak at about the spin fluctuation temperature Tsf deduced from resistivity measurements. Two explanations for these peaks have been postulated: the first is that the peaks are a diffusion thermopower component involving scattering off localized spin fluctuations (LSF) at the impurity sites; the second is that they are an LSF drag effect. We examine the thermopower and resistively of two nearly magnetic alloy systems: Rh(Fe) and Pt(Ni). In the first part of this thesis we describe measurements of the low temperature thermopower and resistivity of several Rh(Fe) alloys to clarify discrepancies in previous measurements and we show, by using a modified Nordheim-Gorter analysis, that the observed thermopower peaks are a diffusion and not a drag effect. In the second part of the thesis we describe measurements of the low temperature thermopower and resistivity of Pt (Ni), for which no previous data had been available. The Pt(Ni) samples are manufactured as thin, evaporated films on glass substrates. However, due to the difficulty encountered in controlling the very high residual resistivity of these samples, we are not able to draw definite conclusions regarding either the thermopower or the resistivity.</p>

scholarly journals The Thermopower and Resistivity of Nearly Magnetic Dilute Alloys

2021 ◽  
Author(s):  
◽  
Constantin Wassilieff
Keyword(s):  
Low Temperature ◽  
Spin Fluctuation ◽  
Residual Resistivity ◽  
Spin Fluctuations ◽  
Magnetic Alloy ◽  
Drag Effect ◽  
Glass Substrates ◽  
Dilute Alloys ◽  
Fluctuation Temperature ◽  
Impurity Sites

<p>In some nearly magnetic dilute alloys, in which the host and impurity are transition metals of similar electronic structure, the thermopower is observed to form a "giant" peak at about the spin fluctuation temperature Tsf deduced from resistivity measurements. Two explanations for these peaks have been postulated: the first is that the peaks are a diffusion thermopower component involving scattering off localized spin fluctuations (LSF) at the impurity sites; the second is that they are an LSF drag effect. We examine the thermopower and resistively of two nearly magnetic alloy systems: Rh(Fe) and Pt(Ni). In the first part of this thesis we describe measurements of the low temperature thermopower and resistivity of several Rh(Fe) alloys to clarify discrepancies in previous measurements and we show, by using a modified Nordheim-Gorter analysis, that the observed thermopower peaks are a diffusion and not a drag effect. In the second part of the thesis we describe measurements of the low temperature thermopower and resistivity of Pt (Ni), for which no previous data had been available. The Pt(Ni) samples are manufactured as thin, evaporated films on glass substrates. However, due to the difficulty encountered in controlling the very high residual resistivity of these samples, we are not able to draw definite conclusions regarding either the thermopower or the resistivity.</p>

LOW TEMPERATURE SPECIFIC HEAT OF YBa2Cu3O7

1993 ◽  
Vol 07 (01n03) ◽  
pp. 166-169 ◽  
Author(s):  
R. CASPARY ◽  
P. HELLMANN ◽  
T. WOLF ◽  
F. STEGLICH
Keyword(s):  
Low Temperature ◽  
Magnetic Fields ◽  
Specific Heat ◽  
Spin Glass ◽  
Oxygen Content ◽  
Theoretical Models ◽  
Specific Heat Data ◽  
Field Dependent ◽  
Low Temperature Specific Heat ◽  
Heat Data

We show specific heat data in magnetic fields to B = 8T on new polycrystals with different oxygen content and compare them with earlier results. The analysis reveals a field dependent residual linear term which is discussed within theoretical models of Bulaevskii and for a spin-glass.

scholarly journals Efficient fluctuation-exchange approach to low-temperature spin fluctuations and superconductivity: From the Hubbard model to NaxCoO2·yH2O

2021 ◽  
Vol 103 (20) ◽  
Author(s):  
Niklas Witt ◽  
Erik G. C. P. van Loon ◽  
Takuya Nomoto ◽  
Ryotaro Arita ◽  
Tim O. Wehling
Keyword(s):  
Low Temperature ◽  
Hubbard Model ◽  
Spin Fluctuations

MAGNETIC PROPERTIES OF U1-xDyxAlyNi5-y (y=0,1) SYSTEMS

2003 ◽  
Vol 17 (27n28) ◽  
pp. 1453-1460
Author(s):  
ILEANA LUPSA
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Spin Fluctuation ◽  
Magnetic Moments ◽  
Transition Temperatures ◽  
Temperature Range ◽  
Fluctuation Model ◽  
Magnetically Ordered

The magnetic properties of U 1-x Dy x Al y Ni 5-y (y=0,1) systems were investigated in the 2(5)–600 K temperature range and for fields up to 80 kOe. The systems having x≥0.2 are magnetically ordered with low transition temperatures and magnetization mainly due to the Dy contribution. The nickel exhibits magnetic moments, very weak in the low temperature range and well-defined effective moments over transition temperatures. The nickel behavior is discussed in terms of the spin fluctuation model.

Description of pressure cells suitable for low temperature specific heat and magnetization measurements

Cryogenics ◽  
1979 ◽  
Vol 19 (9) ◽  
pp. 543-546 ◽  
Author(s):  
A. Berton ◽  
J. Chaussy ◽  
B. Cornut ◽  
J. Odin ◽  
J. Paureau ◽  
...  
Keyword(s):  
Low Temperature ◽  
Specific Heat ◽  
Magnetization Measurements ◽  
Low Temperature Specific Heat

Magnetic Anisotropy in Single Crystals of Zn–Mn and Zn–Cr

1974 ◽  
Vol 52 (18) ◽  
pp. 1759-1764 ◽  
Author(s):  
F. T. Hedgcock ◽  
S. Lenis ◽  
P. L. Li ◽  
J. O. Ström-Olsen ◽  
E. F. Wassermann
Keyword(s):  
Low Temperature ◽  
Magnetic Fields ◽  
Magnetic Anisotropy ◽  
Single Crystals ◽  
Crystal Field ◽  
Interaction Effects ◽  
Crystal Field Splitting ◽  
High Magnetic Fields ◽  
Field Splitting ◽  
Chromium Ion

We have extended the low temperature magnetic anisotropy measurements on single crystals of zinc containing up to 600 p.p.m. manganese from magnetic fields of 9 to 56 kG. The crystal field splitting parameters determined at low magnetic fields also characterizes the magnetic anisotropy at high magnetic fields. Manganese–manganese interaction effects are observed in the magnetic anisotropy at manganese concentrations greater than 300 p.p.m. Low temperature magnetic anisotropy measurements on single crystals of zinc containing up to 164 p.p.m. chromium are reported and indicate a crystal field splitting of 0.16 K for the chromium ion.

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