Magnetic properties of NiCr alloys
01 Feb 1972-Physica Status Solidi B-basic Solid State Physics (WILEY‐VCH Verlag)-Vol. 49, Iss: 2, pp 597-607
TL;DR: In this paper, the magnetization measurements on NiCr alloys were analyzed in terms of the itinerant band model of very weak ferromagnetism and several characteristic properties related to the effective exchange interaction and to the band structure near the Fermi level were deduced from this analysis.
Abstract: New magnetization measurements on NiCr alloys are reported. At increasing Cr concentrations c less than 11 at%, the mean atomic moment M0 = 0 for c = 12 at% Cr. In the critical concentration range, 11 < c < 15 at% Cr, the experimental data are analysed in terms of the itinerant band model of very weak ferromagnetism. Several characteristic properties related to the effective exchange interaction and to the band structure near the Fermi level are deduced from this analysis.
Des mesures d'aimantation d'alliages NiCr ont ete effectuees. Pour c<11% at., on observe une decroissance lineaire du moment magnetique par atome moyen M0 = 0,616 μB – 0,051 c μB. Cette partie lineaire s'extrapole a zero pour c = 12% at. Cr. Les resultats obtenus dans la region critique de disparition du ferromagnetisme, 11 < c <15% at. Cr. ont ete analyses dans un modele d'electron collectif applique au cas du ferromagnetisme tres faible. On en deduit plusieurs proprietes caracteristiques en rapport avec l'interaction d'echange effective et la densite d'etat au niveau de Fermi.
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TL;DR: In this article, the magnetic properties of a series of biaxially textured Ni1� xWx materials with compositions x ¼ 0, 3, 5, 6, and 9 at.
Abstract: A study has been conducted on the magnetic properties of a series of biaxially textured Ni1� xWx materials with compositions x ¼ 0; 3; 5; 6, and 9 at.% W. These materials are important as substrates for ‘‘RABiTS’’-type coated conductors that incorporate high temperature superconductors for current transport. The quasi-static dc and ac hysteretic loss W was determined to support estimates of the ferromagnetic contribution to the overall ac loss in potential ac applications. The alloys were prepared by either vacuum casting or powder metallurgy methods, and the hysteretic loss tended to be lower in materials that were recrystallized at higher temperatures. Some samples were progressively deformed (0.4% bending strain) to simulate winding operations; this increased the hysteretic loss, as did sample cutting operations that create localized damage. In ac magnetization measurements, the effects of ac frequency and dc bias field on the ferromagnetic loss were determined. � 2003 Elsevier B.V. All rights reserved.
104 citations
102 citations
TL;DR: In this article, the lattice, electronic, and magnetic contributions to the specific heat have been separated based on first-principles methods in NiCo, NiFe, Ni-20Cr and NiCoFeCr.
99 citations
TL;DR: A series of biaxially textured Ni1−xCrx materials, with compositions x=0, 7, 9, 11, and 13 at.%Cr, have been studied for use as substrate materials in coated conductor applications with high temperature superconductors as discussed by the authors.
Abstract: A series of biaxially textured Ni1−xCrx materials, with compositions x=0, 7, 9, 11, and 13 at.%Cr, have been studied for use as substrate materials in coated conductor applications with high temperature superconductors. The magnetic properties were investigated, including the hysteretic loss in a Ni–7at.%Cr sample that was controllably deformed; for comparison, the loss was also measured in a similarly deformed pure Ni substrate. Complementary X-ray diffraction studies show that thermomechanical processing produces nearly complete {1 0 0}〈1 0 0〉 cube texturing, as desired for applications.
67 citations
TL;DR: In this article, the authors studied the high field susceptibility of nickel-platinum alloys in fields up to 150 kOe, at temperatures between 4.2 and 300 K. The results were compared with those obtained for palladium-nickel alloys.
Abstract: The authors have studied the high field susceptibility of nickel-platinum alloys in fields up to 150 kOe, at temperatures between 4.2 and 300K. The high field susceptibility is analysed in the ferromagnetic and paramagnetic range by means of Arrott plots and Landau coefficients. The paramagnetic initial susceptibility follows a Curie-Weiss law, with a Curie constant independent of nickel concentration. The results are compared with those obtained for palladium-nickel alloys. The experimental data are discussed in the framework of recent theories on itinerant ferromagnetism.
63 citations
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TL;DR: In this paper, the electron correlation in a narrow energy band is discussed taking into account the multiple scattering between two electrons, and an approximate expression of the effective magnitude of the interaction is derived.
Abstract: The electron correlation in a narrow energy band is discussed taking into account the multiple scattering between two electrons. The discussion is an adaptation of Brueckner's theory of nuclear matter. It is assumed that electrons interact with each other only when they are at the same atom. The effect of the electron correlation depends in an intricate way on the energy spectrum of a given band. An approximate expression of the effective magnitude of the interaction is derived. The condition for the occurrence of ferromagnetism is investigated for various types of bands. The ferromagnetism of Ni and the paramagnetism of Pd can be understood reasonably through the present approach. The degeneracy of the d bands is taken into account in the discussion of these metals. (auth)
1,383 citations
TL;DR: In this article, a criterion for determining the onset of ferromagnetism in a material as its temperature is lowered from a region in which the linearity of its magnetic moment versus field isotherm gives an indication of paramagnetisms.
Abstract: A criterion is proposed for determining the onset of ferromagnetism in a material as its temperature is lowered from a region in which the linearity of its magnetic moment versus field isotherm gives an indication of paramagnetism. Within the limits of validity of a molecular field treatment, the Curie temperature is shown to be in general indicated by the third power of the magnetization being proportional to the internal magnetic field. The method has been employed to redetermine the Curie point of nickel from the data of Weiss and Forrer, of ${\mathrm{Fe}}_{3}$${\mathrm{O}}_{4}$ from the data of Smith and of some alloys from the data of Kaufmann and his collaborators and the author.
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TL;DR: In this paper, a single-band model Hamiltonian is used to describe the electronic structure of a three-dimensional disordered binary alloy, and several common theories based on the single-site approximation in a multiple-scattering description are compared with exact results for this Hamiltonian.
Abstract: A single-band model Hamiltonian is used to describe the electronic structure of a three-dimensional disordered binary alloy. Several common theories based on the single-site approximation in a multiple-scattering description are compared with exact results for this Hamiltonian. The coherent-potential theory of Soven and others is shown to be the best of these. Within the appropriate limits, it exhibits dilute-alloy, virtual-crystal, and well separated impurity-band behavior. Hubbard and Onodera's and Toyozawa's simple model density of states is employed in numerical calculations for a wide variety of concentrations and scattering-potential strengths. Explicit results are exhibited for the total density of states, the partial density contributed by each component, and such $k$-dependent properties as the Bloch-wave spectral density and the distribution function. These illustrate the general conclusions as well as the limitations of the quasiparticle description.
1,025 citations