The Thermopower and Resistivity of Nearly Magnetic Dilute Alloys

10.26686/wgtn.16945864.v1 ◽

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>

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Low-Temperature Spin Fluctuations beyond Spin Waves

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.233-234.20 ◽

2015 ◽

Vol 233-234 ◽

pp. 20-24 ◽

Cited By ~ 2

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.

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Field Dependent Susceptibility and Localized Spin Fluctuations in PdRhNi Alloys

Canadian Journal of Physics ◽

10.1139/p75-021 ◽

1975 ◽

Vol 53 (2) ◽

pp. 145-150 ◽

Cited By ~ 6

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.

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Resistivity of Fe/Al Multilayered Thin Films from Low Temperature to Room Temperature

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.f8970.029320 ◽

2020 ◽

Vol 9 (3) ◽

pp. 39-43

Keyword(s):

Low Temperature ◽

Residual Resistivity ◽

Residual Resistivity Ratio ◽

Resistivity Ratio ◽

Glass Substrates ◽

Increasing Temperature ◽

First Time ◽

Multilayered Thin Films ◽

Deposition Techniques ◽

Metallic Region

By using electron beam gun and thermal deposition techniques in the vacuum range 6 x10-5mbar. The pure materials of 99.99% purity of iron and aluminium multilayers films grown on glass substrates at 300K in the following viz. The resistance was measured using four probe method at UGC-DAE Consortium Indore (4.2K to 300K) later resistivity, conductivity, temperature co-efficient of resistance (TCR), residual resistivity ratio (RRR) , and activation energy(Ea) were calculated. The resistivity behavior shown that the resistivity is increased with increasing the n value, resistivity is increased with increasing temperature. The data belonging to metallic region has been analyzed using the conventional power law’s and it is first time this set of films have explore resistivity at low temperature.

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

Physical Review B ◽

10.1103/physrevb.103.205148 ◽

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

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

Modern Physics Letters B ◽

10.1142/s0217984903006529 ◽

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.

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Theory of the Low-Temperature Properties of Nearly Ferromagnetic Dilute Alloys

Physical Review Letters ◽

10.1103/physrevlett.20.1040 ◽

1968 ◽

Vol 20 (19) ◽

pp. 1040-1044 ◽

Cited By ~ 57

Author(s):

S. Engelsberg ◽

W. F. Brinkman ◽

S. Doniach

Keyword(s):

Low Temperature ◽

Dilute Alloys

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Electrical Characteristics of Al-Y Dilute Alloys under Low-Temperature Plastic Deformation

Advances in Cryogenic Engineering Materials ◽

10.1007/978-1-4757-9053-5_175 ◽

1994 ◽

pp. 1377-1382 ◽

Cited By ~ 1

Author(s):

Sergey Demyanov ◽

Alexander Drozd ◽

Alexander Petrov ◽

Sergey Zakatov

Keyword(s):

Plastic Deformation ◽

Low Temperature ◽

Electrical Characteristics ◽

Dilute Alloys

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Properties of InGaN deposited on Glass at Low Temperature

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300001551 ◽

1997 ◽

Vol 2 ◽

Cited By ~ 11

Author(s):

Tilman Beierlein ◽

S. Strite ◽

A. Dommann ◽

D. J. Smith

Keyword(s):

Low Temperature ◽

Indium Tin Oxide ◽

High Electron ◽

Transparent Conductor ◽

High Background ◽

X Ray ◽

Substrate Heating ◽

Glass Substrates ◽

High Electron Concentration ◽

Background Absorption

We have investigated the properties of InGaN grown at low temperature on glass substrates by a plasma enhanced MBE process. The goal of this study was to evaluate the potential of InGaN as an oxide-free, transparent conductor material which could be deposited at or slightly above room temperature with minimal interaction or damage to the underlying material. InxGa1−xN films deposited on glass, even without substrate heating, are highly crystalline, but the crystallinity as measured by x-ray degrades at x < 0.5. The microstructure observed by TEM of InGaN films deposited on unheated substrates is highly columnar, with typical column widths of ~10 nm. The optical absorption spectra of InGaN/glass have a distinct absorption edge at the bandgap, but also high background absorption in the bandgap. InxGa1−xN grown on glass (x > 0.5) is conductive due to its high electron concentration. InN electron Hall mobilities > 20 cm2/Vs when grown at 400°C, and ~ 7 cm2/Vs on unheated substrates were obtained. The addition of GaN degraded the electrical properties of the films to a greater extent than it improved the transparency. As a result, the best transparent conductor films were pure InN which, when deposited at 400°C, were half as transparent in the green as an indium tin oxide film having the same sheet resistance.

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