First-principle calculations on color center in Y–Al–O system

Chen, Jun; Xu, Yun; Chen, Dongquan

doi:10.1016/j.nimb.2009.06.052

Cited by 10 publications

(3 citation statements)

References 23 publications

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“…All cation vacancies present defect levels located far from the VBM between roughly 1.5 and 2.5 eV. Oxygen vacancies were found to create deep transition levels at the middle of the band gap between 2.6 and 3.1 eV from the CBM, confirming the deep traps already reported in theoretical and experimental investigations [19,[41][42][43][44]. Regarding interstitials, Al i and Y i species introduce relatively deep levels between ∼1.1 and 2.2 eV from the CBM, while deep levels of oxygen species are found around 2.5 and 3.5 eV above the VBM.…”

Section: Native Point Defectssupporting

confidence: 84%

Computational analysis on native and extrinsic point defects in YAG using the metaGGA SCAN method

et al. 2022

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We report on the computational study of point defects in the well-known Y3Al5O12 (YAG) compound. DFT SCAN and SCAN+U calculations were used to access the electronic properties of the material taking into account both native defects and two substituting dopants, namely Ce and Cr. Defect formation enthalpies and defect concentrations were estimated for different synthesis conditions corresponding to extreme and intermediate limits of the stability diagram of YAG. We demonstrate that YAl antisites at Al octahedral position cannot be avoided whatever the synthesis atmosphere. As expected, VO oxygen vacancies are easily formed under reducing atmospheres. Moreover, we have notably show that the formal Ce 3+ /Ce 4+ charge transition Computational analysis on native and extrinsic point defects in YAG using the metaG level is getting closer to the experimental value for a Hubbard correction Ueff of 5 eV. Last, the electron traps associated to the reduction of Cr 3+ into Cr 2+ species were identified near the conduction band.

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Section: Native Point Defectssupporting

confidence: 84%

Computational analysis on native and extrinsic point defects in YAG using the metaGGA SCAN method

et al. 2022

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“…China Spallation Neutron Source (CSNS) [1,2] complex is designed to provide multidisciplinary platforms for scientific research and applications for national institutions, universities and industries. Spallation, the process in which a heavy nucleus emits a large number of nucleons as a result of being hit by a high-energy particle, thus greatly reducing its atomic weight, has become an important technique for the production of high intensity neutron flux.…”

Section: Introductionmentioning

confidence: 99%

Preliminary shielding analysis in support of the CSNS target station shutter neutron beam stop design

Zhang¹,

Chen²,

Wang³

et al. 2011

Chinese Phys. C

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The construction of China Spallation Neutron Source (CSNS) has been initiated in Dongguan, Guangdong, China. Thus a detailed radiation transport analysis of the shutter neutron beam stop is of vital importance. The analyses are performed using the coupled Monte Carlo and multi-dimensional discrete ordinates method. The target of calculations is to optimize the neutron beamline shielding design to guarantee personal safety and minimize cost. Successful elimination of the primary ray effects via the two-dimensional uncollided flux and the first collision source methodology is also illustrated. Two-dimensional dose distribution is calculated. The dose at the end of the neutron beam line is less than 2.5 μSv/h. The models have ensured that the doses received by the hall staff members are below the standard limit required.

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“…The China Spallation Neutron Source (CSNS) [1,2] complex is designed to provide multidisciplinary platforms for scientific research and applications for national institutions, universities and industries. Spallation, the process in which a heavy nucleus emits a large number of nucleons as a result of being hit by a high-energy particle, thus greatly reducing its atomic weight, has become an important technique for the production of high-intensity neutron fluxes.…”

Section: Introductionmentioning

confidence: 99%

Preliminary shielding analysis for the CSNS target station monolith

et al. 2010

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The construction of the China Spallation Neutron Source (CSNS) has been initiated at Dongguan, Guangdong, China. In spallation neutron sources the target station monolith is contaminated by a large number of fast neutrons whose energies can be as large as those of the protons of the proton beam directed towards the tungsten target. A detailed radiation transport analysis of the target station monolith is important for the construction of the CSNS. The analysis is performed using the coupled Monte Carlo and multi-dimensional discrete ordinates method. Successful elimination of the primary ray effects via the two-dimensional uncollided flux and first collision source methodology is also illustrated. The dose at the edge of the monolith is calculated. The results demonstrate that the doses received by the hall staff members are below the required standard limit.

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First-principle calculations on color center in Y–Al–O system

Cited by 10 publications

References 23 publications

Computational analysis on native and extrinsic point defects in YAG using the metaGGA SCAN method

Computational analysis on native and extrinsic point defects in YAG using the metaGGA SCAN method

Preliminary shielding analysis in support of the CSNS target station shutter neutron beam stop design

Preliminary shielding analysis for the CSNS target station monolith

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