The Influence of Crystal Field on Breadths and Splitting of ESR Lines of Dilute Magnetic Alloys

Plefka, T.

doi:10.1002/pssb.2220510256

Cited by 30 publications

(8 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 9: Experimental and calculated 28 Gd 3+ ESR spectra in Ce1−xGdxFe4P12 for x = 0.001 at the transition from Region I to Region II. The parameters used to calculate the theoretical spectra were the same as those used for the calculation of ∆H(T ) in Fig.…”

Section: +mentioning

confidence: 99%

Thermally activated exchange narrowing of the Gd3+ESR fine structure in a single crystal of Ce1−xGd
Garcia
¹
,
Venegas
²
,
Pagliuso
³

et al. 2011
Phys. Rev. B

View full text Add to dashboard Cite

We report electron spin resonance (ESR) measurements in the Gd 3+ doped semiconducting filled skutterudite compound Ce1−xGdxFe4P12 (x ≈ 0.001). As the temperature, T , varies from T ≃ 150 K to T ≃ 165 K the Gd 3+ ESR fine and hyperfine structures coalesce into a broad inhomogeneous single resonance. At T ≃ 200 K the line narrows and as T increases further the resonance becomes homogeneous with a thermal broadening of 1.1(2) Oe/K. These results suggest that the origin of these features may be associated to a subtle interdependence of thermally activated mechanisms that combine: i) an increase with T of the density of activated conduction-carriers across the Tdependent semiconducting pseudogap; ii) the Gd 3+ Korringa relaxation process due to an exchange interaction, J f d S.s, between the Gd 3+ localized magnetic moments and the thermally activated conduction-carriers and; iii) a relatively weak confining potential of the rare-earth ions inside the oversized (Fe2P3)4 cage, which allows the rare-earths to become rattler Einstein oscillators above T ≈ 148 K. We argue that the rattling of the Gd 3+ ions, via a motional narrowing mechanism, also contributes to the coalescence of the ESR fine and hyperfine structure.

show abstract

Section: +mentioning

confidence: 99%

Thermally activated exchange narrowing of the Gd3+ESR fine structure in a single crystal of Ce1−xGd
Garcia
¹
,
Venegas
²
,
Pagliuso
³

et al. 2011
Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…The coefficient C ( M ) represents the transition probability of the observed ESR transition whose temperature-dependent linewidth is investigat,ed [7] :…”

Section: Discussion Of the Resultsmentioning

confidence: 99%

“…c) Dynamics in the spin system, caused by s-d or s-f exchange, can lead to a narrowing of the crystal field splitting [7] and the hyperfine structure [S].…”

Section: G Sperlich and H M~l L E Rmentioning

confidence: 99%

s–d Interaction in the Transition Range between Metals and Insulators: CdS: Mn

Spehlich

Müller

1975

Physica Status Solidi (b)

View full text Add to dashboard Cite

I n metallic compounds with low charge-carrier concentrations the Korringa relaxation rate can be so small that i t reaches the order of magnitude of the direct spin-lattice relaxation rate. We report on an ESR investigation of Cd8 doped with the S-state ions Mn and Eu, where between both contributions to the homogeneous ESR line-width could be distinguished. Mn-doped CdS turns out t o have an extremely small Korringa slope of the ESR linewidtli. We were able to vary this slope from zero to about 0.02 G/K by variation of the electric conductivity of CdS from insulator to a compound with metallic behavior.I n metallischen Verbindungen mit niedriger Ladungstragerkonzentration kann die Korringa-Relaxationsrate so klein sein, daB sie die GroBenordnung der direkten Spin-Gitter-

show abstract

“…As a consequence of (41), the off-diagonal elements of (32) may be neglected and we obtain Equation ") The discussion of the couplings is not restricted to the resolved spectrum. Doing this for the limits of [9], we obtain that for the isothermal case (see Fig. la and b of [Y]) the two modes are associated to linear combinations of 6 M ; and 6M:,.…”

Section: Completelg Resolved Spectrwlrtmentioning

confidence: 98%

“…), denotes the expectation value performed with H,. For ~( 0 ) the zeroth-order approximation (15) implies (see equations (6 b), (9), and (11)) 3, A general discussion of this approximation is given in [13].…”

Section: Perturbation Theorymentioning

confidence: 98%

Theory of Resolved and Unresolved Crystal Field Structure of ESR Spectra in Dilute Magnetic Alloys

Plefka

1973

Physica Status Solidi (b)

Self Cite

View full text Add to dashboard Cite

The influence of crystal fields on the dynamic transverse susceptibility of localized spin moments coupled to the conduction electrons in a metal is investigated. In Liouville-space, the projector onto the subspace is introduced which is spanned by the transverse component of the conduction electron magnetization and the transition operators of the crystal field energy levels. Within the framework of projector formalism, the susceptibility is expressed in terms of a transition matrix which is then calculated in lowest order perturbation theory. The found explicit expression of the susceptibility is valid for the isothermal case as well as for the bottleneck one. The theoretical predicted resolved and unresolved ESR spectra are discussed for high and low temperature. For the bottleneck and the isothermal case, a resolved spectrum is expected when crystal field splittings are greater than the Korringa relaxation rate.Es wird der EinfluB von Kristallfeldern auf die transversale dynamische Suszeptibilitat lokalisierter Spin-Momente untersucht, die an die Leitungselektronen in einem Metal1 angekoppelt sind. I m Liouville-Raum wird der Projektor auf den Unterraum eingefuhrt, der von der transversalen Komponente der Leitungselektronen-Magnetisierung und den tfbergangsoperatoren der Krist,allfeld-Energiezustande aufgespannt wird. Mit Hilfe des Projektorformalismus wird die Suszeptibilitat durch eine Ubergangsmatrix ausgedriickt, die dann in Storungstheorie niedrigster Ordnung bestimmt wird. Der gefundene explizite Ausdruck fur die Suszeptibilitat ist gultig sowohl fur den isothermen als auch den ,,bottleneck"-Fall. Die theoretisch vorhergesagten aufgelosten und unaufgelosten ESR Spektren werden fur hohe und tiefe Temperaturen diskutiert. Fur den ,,bottleneck" und den isothermen Fall wird ein aufgelostes Spektrum erwartet, falls die Kristallfeldaufspaltung groBer als die Korringa-R.elaxationsrate ist.

show abstract

The Influence of Crystal Field on Breadths and Splitting of ESR Lines of Dilute Magnetic Alloys

Cited by 30 publications

References 4 publications

Thermally activated exchange narrowing of the Gd3+ESR fine structure in a single crystal of Ce1−xGd
Garcia
¹
,
Venegas
²
,
Pagliuso
³

et al. 2011
Phys. Rev. B

Thermally activated exchange narrowing of the Gd3+ESR fine structure in a single crystal of Ce1−xGd
Garcia
¹
,
Venegas
²
,
Pagliuso
³

et al. 2011
Phys. Rev. B

s–d Interaction in the Transition Range between Metals and Insulators: CdS: Mn

Theory of Resolved and Unresolved Crystal Field Structure of ESR Spectra in Dilute Magnetic Alloys

Contact Info

Product

Resources

About

The Influence of Crystal Field on Breadths and Splitting of ESR Lines of Dilute Magnetic Alloys

Cited by 30 publications

References 4 publications

Thermally activated exchange narrowing of the Gd3+ESR fine structure in a single crystal of Ce1−xGdGarcia1, Venegas2, Pagliuso3 et al. 2011Phys. Rev. B

Thermally activated exchange narrowing of the Gd3+ESR fine structure in a single crystal of Ce1−xGdGarcia1, Venegas2, Pagliuso3 et al. 2011Phys. Rev. B

s–d Interaction in the Transition Range between Metals and Insulators: CdS: Mn

Theory of Resolved and Unresolved Crystal Field Structure of ESR Spectra in Dilute Magnetic Alloys

Contact Info

Product

Resources

About

Thermally activated exchange narrowing of the Gd3+ESR fine structure in a single crystal of Ce1−xGd
Garcia
¹
,
Venegas
²
,
Pagliuso
³

et al. 2011
Phys. Rev. B

Thermally activated exchange narrowing of the Gd3+ESR fine structure in a single crystal of Ce1−xGd
Garcia
¹
,
Venegas
²
,
Pagliuso
³

et al. 2011
Phys. Rev. B