Propriétés magnétiques des alliages dilués. Interactions magnétiques et antiferromagnétisme dans les alliages du type métal noble-métal de transition

Blandin, Annie; Friedel, J.

doi:10.1051/jphysrad:01959002002-3016000

Cited by 194 publications

(37 citation statements)

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“…The bound state involved in a classic virtual bound state falls in the Fermi Sea [43,44]. The one-electron bound state energy can be nearly as deep as the potential well far below the free electron band bottom for large radii; these observations could extend the domain of Friedel's virtual bound states to highly charged crystals in metallic melts.…”

Section: Quantum Weakening Of the Electrostatic Energy Savingmentioning

confidence: 91%

Crystal growth nucleation and Fermi energy equalization of intrinsic spherical nuclei in glass-forming melts

Tournier¹

2009

Science and Technology of Advanced Materials

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The energy saving resulting from the equalization of Fermi energies of a crystal and its melt is added to the Gibbs free-energy change G 2ls associated with a crystal formation in glass-forming melts. This negative contribution being a fraction ε ls (T ) of the fusion heat is created by the electrostatic potential energy −U 0 resulting from the electron transfer from the crystal to the melt and is maximum at the melting temperature T m in agreement with a thermodynamics constraint. The homogeneous nucleation critical temperature T 2 , the nucleation critical barrier G * 2ls /k B T and the critical radius R * 2ls are determined as functions of ε ls (T ). In bulk metallic glass forming melts, ε ls (T ) and T 2 only depend on the free-volume disappearance temperature T 0l , and ε ls (T m ) is larger than 1 (T 0l > T m /3); in conventional undercooled melts ε ls (T m ) is smaller than 1 (T 0l > T m /3). Unmelted intrinsic crystals act as growth nuclei reducing G * 2ls /k B T and the nucleation time. The temperature-time transformation diagrams of Mg 65 Y 10 Cu 25 , Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 , Pd 43 Cu 27 Ni 10 P 20 , Fe 83 B 17 and Ni melts are predicted using classic nucleation models including time lags in transient nucleation, by varying the intrinsic nucleus contribution to the reduction of G * 2ls /k B T . The energy-saving coefficient ε nm (T ) of an unmelted crystal of radius R nm is reduced when R nm R * 2ls ; ε nm is quantified and corresponds to the first energy level of one s-electron moving in vacuum in the same spherical attractive potential −U 0 despite the fact that the charge screening is built by many-body effects.

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Section: Quantum Weakening Of the Electrostatic Energy Savingmentioning

confidence: 91%

Crystal growth nucleation and Fermi energy equalization of intrinsic spherical nuclei in glass-forming melts

Tournier¹

2009

Science and Technology of Advanced Materials

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“…Friedel discussed the formation of a magnetic d-impurity in a number of papers qualitatively and quantitatively [3][4][5]13] in the 1950s. In [13], Blandin and Friedel give the mean field criterion for the formation of a magnetic impurity.…”

Section: The Friedel-anderson Impuritymentioning

confidence: 99%

“…In [13], Blandin and Friedel give the mean field criterion for the formation of a magnetic impurity. Since this paper is in French, I sketch briefly the essential equations.…”

Section: The Friedel-anderson Impuritymentioning

confidence: 99%

A Compact Treatment of Singular Impurities Using the Artificial Friedel Resonance (FAIR) Technique

Bergmann

2012

J Supercond Nov Magn

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Building on the tools that Friedel introduced in the 1950s, an off-spring of the Friedel resonance is developed, which is called the FAIR approach for "Friedel Artificially Inserted Resonance". In the FAIR approach, an arbitrary s-electron state a † 0 is cut out of the conduction band, and the remaining free electron Hamiltonian is orthogonalized, yielding an artificial Friedel resonance. In the presence of a real Friedel d-resonance state d † , one can find an optimal fair state a † 0 so that the exact n-electron ground state consists of two Slater states, one containing the d-electron and the other the fair state a † 0 . This separation according to the d-occupation is ideal for impurities with a Coulomb interaction between d-electrons. The wave function of the Friedel-Anderson (FA) impurity in the magnetic state and the singlet state are constructed with the FAIR method using two fair states a † 0 and b † 0 . The magnetic state consists of four, and the singlet state consists of eight Slater states. The latter is invariant with respect to the inversion of all spins. The FAIR ground state Ψ SS for the singlet state is composed of two magnetic states Ψ MS with opposite moments which are not orthogonal to each other. The degree of overlap determines the Kondo energy. Because of the compactness of the wave function, a number of properties can be calculated relatively quickly. Comparison with the best previous ground state energy and d-occupation by Gunnarson and Schoenhammer show excellent agreement. A number of physical properties are calculated; among them are (i) the Kondo cloud in a small magnetic field. Two components of polarization are observed (in linear response), an oscillating part and a nonoscillating part. (ii) The fidelity which represents the scalar product between the ground states of the symmetric FA-impurity and the symmetric Friedel impurity is calculated as a function of the number of electron states. (In the literature, this has the somewhat misleading name of fidelity.) This calculation does not show an Anderson orthogonality catastrophe, which indicates that the FA ground state has a phase shift of π/2 at the Fermi energy. (iii) The Friedel oscillations of the FA-impurity. Surprisingly, these oscillations are very similar to the Friedel oscillations of a very narrow Friedel resonance at the Fermi level. The amplitude A(r) is close to zero at short distances and saturates at two for large distances. The inversion point where A(r) = 1 correlates with the characteristic energies of the impurities, the half-band width Γ for the Friedel impurity and the Kondo energy for the FA-impurity. This raises the fascinating question how these simple properties are hidden in the multielectron wave function.

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“…Вплоть до этого момента практически не уделялось никакого внимания (за исключением работы 6 ) вопросу о том, что же означает наличие магнитного момента в металле: например, детальные исследования поведения Μη в Си, проделанные Оуэном с сотрудниками 9 и Циммерманом 10 , а также расчеты Иосиды а , по существу, постулировали, что в металле имеется локальный атомный спин, обозна-чаемый S и существующий от бога. Пред-полагалось, что подобный спин взаимодей-ствует обменным образом со свободными…”

Section: «модель андерсона»; локализованные моменты в металлахunclassified

Lokal'nye momenty i lokalizovannye sostoyaniya

Anderson¹

1979

Usp. Fiz. Nauk

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Propriétés magnétiques des alliages dilués. Interactions magnétiques et antiferromagnétisme dans les alliages du type métal noble-métal de transition

Cited by 194 publications

References 16 publications

Crystal growth nucleation and Fermi energy equalization of intrinsic spherical nuclei in glass-forming melts

Crystal growth nucleation and Fermi energy equalization of intrinsic spherical nuclei in glass-forming melts

A Compact Treatment of Singular Impurities Using the Artificial Friedel Resonance (FAIR) Technique

Lokal'nye momenty i lokalizovannye sostoyaniya

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