Effect of Reactor Radiation Intensity on Crystal Lattice Expansion in Diamond

Nikolaenko, V. A.; Krasikov, E. A.

doi:10.1007/s10512-014-9782-7

Cited by 7 publications

(6 citation statements)

References 3 publications

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“…The shift of the maxima of the Raman bands (including the diamond band) toward the low-frequency region with increasing fluence is partially explained by the increase in the diamond lattice volume [29] due to the high concentration of defects [30]. The increase in the lattice parameter determined by the XRD method makes a contribution (of up to 6 volume %) to the swelling of RD diamond [29]. The pycnometric swelling reaches a value of 40 volume percents in diamonds in which radiation damage is below the graphitization threshold [31].…”

Section: Raman Spectra Of Neutron-irradiated Diamondsmentioning

confidence: 98%

Probing the Nanostructure of Neutron-Irradiated Diamond Using Raman Spectroscopy

2020

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Disordering of crystal lattice induced by irradiation with fast neutrons and other high-energy particles is used for the deep modification of electrical and optical properties of diamonds via significant nanoscale restructuring and defects engineering. Raman spectroscopy was employed to investigate the nature of radiation damage below the critical graphitization level created when chemical vapor deposition and natural diamonds are irradiated by fast neutrons with fluencies from 1 × 1018 to 3 × 1020 cm−2 and annealed at the 100–1700 °C range. The significant changes in the diamond Raman spectra versus the neutron-irradiated conditions are associated with the formation of intrinsic irradiation-induced defects that do not completely destroy the crystalline feature but decrease the phonon coherence length as the neutron dose increases. It was shown that the Raman spectrum of radiation-damaged diamonds is determined by the phonon confinement effect and that the boson peak is present in the Raman spectra up to annealing at 800–1000 °C. Three groups of defect-induced bands (first group = 260, 495, and 730 cm−1; second group = 230, 500, 530, 685, and 760 cm–1; and third group = 335, 1390, 1415, and 1740 cm−1) were observed in Raman spectra of fast-neutron-irradiated diamonds.

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Section: Raman Spectra Of Neutron-irradiated Diamondsmentioning

confidence: 98%

Probing the Nanostructure of Neutron-Irradiated Diamond Using Raman Spectroscopy

2020

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“…A change in the microstructure of a material during radiation damage leads to its swelling due to a decrease in density. This phenomenon is observed in all materials, but in diamond, it is most pronounced and is accompanied by an increase in the crystal lattice parameter, determined by X-ray [74] and neutron [48] diffraction. Strong (up to 40 vol.%) swelling in radiation-damaged diamond is one of the evidences in favor of the hypothesis of the formation of an amorphous material with density of ≈2 g/cm 3 [71,77,78] and poorly manifested in X-ray diffraction.…”

Section: Raman Spectra Of Neutron-irradiated Diamondsmentioning

confidence: 89%

“…The selection for magnetic measurements of natural diamond grains irradiated with fast neutrons was carried out according to Raman scattering data on the basis of the intensity criterion and the spectral position of the "1640" band (see Figure 2), i.e., having the highest subcritical level of radiation damage. Rapid changes near the critical level of radiation damage of diamond in the spectral position of the "1640" band and the intensity of this band in comparison with the boson band (Figure 2) demonstrate the advantage of this technique over establishing the level of diamond critical damage based on the calculated value of vacancies [71] as deduced from the TRIM [72] computer code, the magnitude of mechanical stresses in the ion-implanted layer [73], or by the value of crystal lattice expansion [74]. The necessity of selecting diamonds for magnetic measurements is conditioned by different levels of radiation damage of diamond grains simultaneously irradiated in the fast reactor neutron flux (due to local variations of heat dissipation conditions).…”

Section: Raman Spectra Of Neutron-irradiated Diamondsmentioning

confidence: 98%

“…Decomposition of the "1640" band into Lorentz contours (Figure 4) showed that it consists of at least three components with maxima near 1465, 1530, and 1620 cm −1 , and the four main components of the second-order band are presumably overtones of the "1640" band components with frequencies approximately equal to twice the firstorder frequencies (2925, 3050 and 3230 cm −1 , respectively) and a combination of the 1530 + 1620 cm −1 (≈ 3135 cm −1 ) components. In this case, it should be kept in mind that the lattice parameter of neutron-irradiated crystals is increased compared to unirradiated diamond [48,74], which causes a shift of the bands in the Raman spectra to the low-frequency region [49,54,55,67].…”

Section: Raman Spectra Of Neutron-irradiated Diamondsmentioning

confidence: 99%

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Magnetic and Optical Properties of Natural Diamonds with Subcritical Radiation Damage Induced by Fast Neutrons

et al. 2023

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Raman spectroscopy and magnetic properties of the natural single crystalline diamonds irradiated with high fluences of fast reactor neutrons have been investigated. Raman spectra transformations were studied in the range from moderate levels up to radiation damage leading to diamond graphitization. The selection of fast neutrons irradiated diamonds for magnetic measurements was carried out according to Raman scattering data on the basis of the intensity criterion and the spectral position of the “1640” band. It was found that in natural diamonds irradiated with neutrons with an extremely high subcritical fluence F = 5 × 1020 cm−2, the transition from a diamagnetic to a ferromagnetic state is observed at the Curie–Weiss temperature of ≈150 K. The energy of the exchange magnetic interaction of uncompensated spins is estimated to be ≈1.7 meV. The differential magnetic susceptibility estimated from the measurements of magnetic moment for temperature 2 K in the limit of B ≈ 0 is χdiff ≈ 1.8 × 10−3 SI units. The nature of magnetism in radiation-disordered single-crystal hydrogen- and metal-free natural diamond grains was discussed.

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“…Highly sensitive PL methods can distinguish individual impurity and defect centers [2,6], that can be used to get impurity/defect distribution in the irradiated layer [7]. As known, any radiation damage of diamond lattice leads to its swelling [8][9][10][11][12][13][14]. Structural disorder induced by low energy ions (tens to hundreds keV) is localized near the surface.…”

Section: Introductionmentioning

confidence: 99%