Electron spin resonance and nuclear magnetic resonance of sodium macrostructures in strongly irradiated NaCl-K crystals: Manifestation of quasi-one-dimensional behavior of electrons

Cherkasov, F. G.; Mustafin, R. G.; L’vov, S.G.; Denisenko, G. A.; Hartog, HW den; Vainshtein, D.I.

doi:10.1134/1.567649

Cited by 3 publications

(17 citation statements)

References 9 publications

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“…1a), g ¼ 2.0014 (Fig. 1c), at the melting point the ESR linewidth increases by an amount of $5.5 G, an isotropic Knight shift K ¼ 0.11% (see [3,4]). The ESR linewidth depends on the defect state of the damaged crystals, and at 300 K our NaCl-K and NaCl-KBF 4 samples yield linewidths of 21 and 18 G, respectively (Fig.…”

Section: High Temperature (Range I)mentioning

confidence: 95%

“…There is considerable interest in electron-irradiated NaCl-X crystals (X ¼ K or KBF 4 ) since at high doses and large dose rates non-equilibrium structural changes appear and conducting channels, consisting of extremely small metallic sodium particles, might be formed [1][2][3][4]. The electronic and magnetic properties of these crystals are similar to those of quasi-onedimensional conducting and polymeric compound RbC 60 (see [5,6]).…”

Section: Introductionmentioning

confidence: 95%

“…The electronic and magnetic properties of these crystals are similar to those of quasi-onedimensional conducting and polymeric compound RbC 60 (see [5,6]). Indeed, NMR spin relaxation [3,4,7], conduction electron spin resonance (CESR) and differential scanning calorimetry (DSC) [2,8] all suggest that NaCl-X is an electrical conductor above 160 K. However, between 160 and 40 K a gradual decrease of the CESR susceptibility with decreasing temperature has been observed. This was interpreted as evidence for the transition of NaCl-K to a non-conductive charge-density-wave (CDW) state [3] and indicative of small antiferromagnetic (AF) spin fluctuations persisting in heavily irradiated NaCl-KBF 4 crystals up to 160 K [2].…”

Section: Introductionmentioning

confidence: 98%

“…Indeed, NMR spin relaxation [3,4,7], conduction electron spin resonance (CESR) and differential scanning calorimetry (DSC) [2,8] all suggest that NaCl-X is an electrical conductor above 160 K. However, between 160 and 40 K a gradual decrease of the CESR susceptibility with decreasing temperature has been observed. This was interpreted as evidence for the transition of NaCl-K to a non-conductive charge-density-wave (CDW) state [3] and indicative of small antiferromagnetic (AF) spin fluctuations persisting in heavily irradiated NaCl-KBF 4 crystals up to 160 K [2]. One of the reasons for electron spins to align at low temperatures is the strong exchange interaction with F-aggregate centers, which are the relevant paramagnetic defects in heavily irradiated NaCl-X at low temperatures [2,3].…”

Section: Introductionmentioning

confidence: 98%

“…This was interpreted as evidence for the transition of NaCl-K to a non-conductive charge-density-wave (CDW) state [3] and indicative of small antiferromagnetic (AF) spin fluctuations persisting in heavily irradiated NaCl-KBF 4 crystals up to 160 K [2]. One of the reasons for electron spins to align at low temperatures is the strong exchange interaction with F-aggregate centers, which are the relevant paramagnetic defects in heavily irradiated NaCl-X at low temperatures [2,3].…”

Section: Introductionmentioning

confidence: 98%

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The ground state of metallic nano-structures in heavily irradiated NaCl-KBF 4

Cherkasov

L’vov

Тихонов

et al. 2002

Radiation Effects and Defects in Solids

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ESR, NMR and static magnetic susceptibility measurements of heavily irradiated NaCl-K and NaCl-KBF 4 are reported. Up to 10% of the NaCl-molecules are transformed into metallic Na nanoparticles and Cl 2 precipitates. In addition, there are paramagnetic F-and F-aggregates, which are coupled by exchange interactions to the conduction electrons in the nanoparticles. Above 160 K the NMR and ESR signals of NaCl-K and NaCl-KBF 4 show Pauli paramagnetism and the properties of the Na nanoparticles are similar to bulk sodium. A single ESR line is observed revealing exchange interaction between conduction electrons in the nano-particles and F-aggregates. The observed decrease of the ESR susceptibility with decreasing temperature is due to a metalinsulator transition. The conduction electrons are localized below 40 K and the above mentioned F-aggregate centers contribute significantly to the overall ESR signal. For NaCl-KBF 4 we observed that with decreasing temperature the ESR line shifts towards lower fields due to antiferromagnetic ordering and internal magnetic fields.

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Section: High Temperature (Range I)mentioning

confidence: 95%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

See 3 more Smart Citations

The ground state of metallic nano-structures in heavily irradiated NaCl-KBF 4

Cherkasov

L’vov

Тихонов

et al. 2002

Radiation Effects and Defects in Solids

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Metal$ndash$insulator and magnetic transitions in heavily irradiated NaCl$ndash$KBF4

Cherkasov

L’vov

Тихонов

et al. 2002

J. Phys.: Condens. Matter

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We have performed electron spin resonance (ESR), nuclear magnetic resonance (NMR) and static magnetic susceptibility measurements on heavily irradiated NaCl-KBF 4 single crystals in the temperature range 4.2 < T < 350 K. In these samples, up to about 10% of the NaCl molecules are transformed into extremely small metallic Na particles and Cl 2 precipitates. At high temperatures a oneline ESR signal, i.e. common mode due to strong exchange interaction between conduction electrons and F-aggregate centres, is observed. We propose that the smooth decrease of the ESR spin susceptibility with decreasing temperature, which can be as large as 50%, is due to a metal-insulator transition, taking place at about 40 K. In the same temperature range, the linewidth increases by 18±2 G with decreasing temperature. This anomalous broadening is explained by a reduction of the exchange narrowing at low temperatures. NMR spinlattice relaxation on 23 Na shows a Korringa-type behaviour down to 10 K, which suggests that the conducting phase in heavily irradiated NaCl-KBF 4 behaves as a three-dimensional metal. SQUID experiments have revealed antiferromagnetic ordering at 40 K and a ferromagnetic phase below 20 K. The nature of the observed effects is discussed.

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Radiolysis of NaCl at high and low temperatures: development of size distribution of bubbles and colloids

Turkin¹,

Sugonyako²,

Vainshtein³

et al. 2006

J. Phys.: Condens. Matter

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New experimental results are presented on low temperature irradiation (18 • C) of rock-salt samples which had been exposed to initial doses up to 320 GRad at 100 • C. Differential scanning calorimetry (DSC) shows that the latent heat of melting (LHM) of sodium colloids decreases during subsequent lowtemperature irradiation, whereas the stored energy (SE) increases slowly, indicating that the process of radiolysis continues. The decrease of the LHM is due to dissolution of large colloids, because the intensities of the melting peaks decrease during the second stage irradiation at low temperature. The model is formulated to describe the nucleation kinetics and the evolution of the size distribution of chlorine precipitates and sodium colloids in NaCl under high dose irradiation. It is shown that the mechanism of dissolution of large Na colloids during low temperature irradiation can be related to melting of sodium colloids.

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Electron spin resonance and nuclear magnetic resonance of sodium macrostructures in strongly irradiated NaCl-K crystals: Manifestation of quasi-one-dimensional behavior of electrons

Abstract: Electron spin resonance and nuclear magnetic resonance of sodium macrostructures in strongly irradiated NaCl-K crystals: Manifestation of quasi-one-dimensional behavior of electrons.

Cited by 3 publications

References 9 publications

The ground state of metallic nano-structures in heavily irradiated NaCl-KBF 4

The ground state of metallic nano-structures in heavily irradiated NaCl-KBF 4

Metal$ndash$insulator and magnetic transitions in heavily irradiated NaCl$ndash$KBF4

Radiolysis of NaCl at high and low temperatures: development of size distribution of bubbles and colloids

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