Paramagnetische Resonanz (ESR‐ und ENDOR‐Spektroskopie) von Farbzentren in Alkalihalogenid‐Kristallen

Seidel, H.; Wolf, Hans Christoph

doi:10.1002/pssb.19650110102

Cited by 44 publications

(3 citation statements)

References 155 publications

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“…This is an approximation of the effective field approach [14]. The latter is restricted to cases where IQijl < W s h f .…”

Section: Endor Frequency Ofmentioning

confidence: 99%

ENDOR investigations of Cr⁺ centres in NaF, NaCl, and NaBr

Ziegler

1972

Physica Status Solidi (b)

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Isolated paramagnetic Cr+ centres in sodium halide crystals are studied by E P R and ENDOR. They show cubic symmetry. Superhyperfine and quadrupole interactions with many neighbouring ions (up to (300) in NaF) could be determined. The experimental results are interpreted in terms of two models for the wavefunction of the centre: overlap and covalency. A new way for the experimental determination of the coefficients for B-and x-covalency, using the isotropic superhyperfine interactions of neighbours (1 10) and (200), is proposed. The small anisotropic superhyperfine interaction of the nearest neighbours, which becomes even negative for Br-in NaBr, cannot be understood along these lines.Isolierte paramagnetische Cr+-Zentren in Natriumhalogenideinkristallen wurde mit ESR und ENDOR untersucht. Sie zeigen kubische Symmetrie. Superhyperfein-und Quadrupolwechselwirliungen mit zahlreichen Nachbarkernen (bis zum Kern (300) in NaF) konnten bestimmt werden. Die experimentellen Ergebnisse werden anhand von zwei Modellen fur die Zentrenwellenfunktion diskutiert : tfberlappung und Kovalenz. Daraus ergibt sich eine neue Methode zur experimentellen Bestimmung der Koeffizienten von B-und x-Kovalenz, indem man die isotropen Superhyperfeinwechselwirkungen der Nachbarn (1 10) und (200) heranzieht. Die kleine anisotrope Superhyperfeinwechselwirkung mit den nachsten Nachbarn, die fur Br-in NaBr sogar negativ wird, kann auf diese Weise nicht erklart werden.

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“…This is an approximation of the effective field approach [14]. The latter is restricted to cases where IQijl < W s h f .…”

Section: Endor Frequency Ofmentioning

confidence: 99%

ENDOR investigations of Cr⁺ centres in NaF, NaCl, and NaBr

Ziegler

1972

Physica Status Solidi (b)

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“…Once formed, the (6,&) center, with its relatively high mobility, can migrate to form an M center according to the steps (2)9 (3), and (4). As the bleaching proceeds, the average distance between an F center and an G center tends to increase and consequently the probability of formation of (a,&) centers tends to decrease.…”

Section: Bleaching Efficiencymentioning

confidence: 99%

Optical and electron paramagnetic resonance studies of sodium fluoride

Andrews

1966

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“…The signs ± refer to m -±4. Every Si-nucleus (mi-1) gives rise to two ENDOR transitions [5]. In Fig.2 these 29Si ENDOR transitions are denoted a'-to dthey can be clearly seen nearly symmetrically around vk(29Si) for the Cz-Si sample.…”

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confidence: 94%

The Structure of Thermal Donors (NL8) in Silicon: a Model Derived From ¹⁷O and ²⁹SI Endor Experiments

1987

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Results of new electron nuclear double resonance (ENDOR) experiments on the thermal donors (NL8) in silicon are presented. Hyperfine interactions (hi) with 170 were observed. Two types of oxygen were found, of each type there are at least two oxygen atoms. The size and tensor orientations of their hf interactions are consistent with the presence of four oxygen atoms with approx. <111>-symmetry in the core of the thermal donors.Heat treatment of Cz grown, oxygen-rich Si at about 450 0 C leads to the formation of oxygen-related, electrically active shallow donors, called 'thermal donors' (TD) [1]. Although there have been many attemps to determine the microscopic structure, it is still unknown. TD's are assumed to consist of small complexes containing oxygen, although this was contested recently [2]. From infrared measurements is known, that several different TD-species are formed with increasing annealing time [3]. Our previous ENDOR-investigations showed, that all singly ionised TD-species are superimposed in the one ESR line "NL8" [4]. In these ENDOR-measurements only 29 Si-interactions were observed, since the predominant 160 isotope has no nuclear moment. The magnetic 170 isotope has a natural abundance of only 3.7x10-2 %. In order to resolve 0 hyperfine (hf) interactions it was necessary to diffuse 170 enriched oxygen into oxygen free FZ-Si. B-doped Si was used with a B concentration of 4x10 5

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Paramagnetische Resonanz (ESR‐ und ENDOR‐Spektroskopie) von Farbzentren in Alkalihalogenid‐Kristallen

Cited by 44 publications

References 155 publications

ENDOR investigations of Cr⁺ centres in NaF, NaCl, and NaBr

ENDOR investigations of Cr⁺ centres in NaF, NaCl, and NaBr

Optical and electron paramagnetic resonance studies of sodium fluoride

The Structure of Thermal Donors (NL8) in Silicon: a Model Derived From ¹⁷O and ²⁹SI Endor Experiments

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Paramagnetische Resonanz (ESR‐ und ENDOR‐Spektroskopie) von Farbzentren in Alkalihalogenid‐Kristallen

Cited by 44 publications

References 155 publications

ENDOR investigations of Cr+ centres in NaF, NaCl, and NaBr

ENDOR investigations of Cr+ centres in NaF, NaCl, and NaBr

Optical and electron paramagnetic resonance studies of sodium fluoride

The Structure of Thermal Donors (NL8) in Silicon: a Model Derived From 17O and 29SI Endor Experiments

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Resources

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ENDOR investigations of Cr⁺ centres in NaF, NaCl, and NaBr

ENDOR investigations of Cr⁺ centres in NaF, NaCl, and NaBr

The Structure of Thermal Donors (NL8) in Silicon: a Model Derived From ¹⁷O and ²⁹SI Endor Experiments