Change of the self-diffusion of 58Co in Co79Nb14B7 during transition from the amorphous to the nanocrystalline phase

Schuler, Thomas M.; Pavlovský, J.; Scharwaechter, P.; Ulfert, W.; Frank, W.

doi:10.1016/0965-9773(95)00196-4

Cited by 7 publications

(7 citation statements)

References 6 publications

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“…It is well established for certain amorphous alloys (AMA) [1][2][3][4][5][6][7][8][9] that the diffusion coefficient of tracer atoms in well-relaxed specimens decreases compared to as-quenched ones. Usually, this effect has been interpreted as the existence of quasivacancies in super-saturation.…”

Section: Introductionmentioning

confidence: 99%

Evidence of ‘microscopic bubbles’ and a new diffusion mechanism for amorphous alloys

Hung

Kien²,

Vinh³

2009

J. Phys.: Condens. Matter

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Simulation of the diffusion mechanism in amorphous alloys is carried out using three statistical relaxation models Fe(80)B(20) with 10(5) atoms. We found for the first time that the simulated models contain a large number of vacancy bubbles, which could be a diffusion vehicle such as a vacancy, as in the case of diffusion in a crystal. The numbers of these vacancy bubbles vary from 2.8 × 10(-3) to 1.245 × 10(-2) per atom depending on the relaxation degree. Diffusion coefficients have been calculated via the vacancy bubbles and they are very consistent with experiment. The relaxation effect is also studied and interpreted as a result of vacancy-bubble annihilation during thermal annealing.

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Section: Introductionmentioning

confidence: 99%

Evidence of ‘microscopic bubbles’ and a new diffusion mechanism for amorphous alloys

Hung

Kien²,

Vinh³

2009

J. Phys.: Condens. Matter

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“…In addition, as-quenched AMA suffers from large number of vacancies in supersaturation which quickly annihilates upon relaxation. Consequently, the diffusion constant decreases and reaches a final value until the relaxation is over, for example, the system is transposed into a well-relaxed state [7,8]. As such, the vacancy diffusion model enables the interpretation the relaxation effect which is observed experimentally in certain AMAs [9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 98%

Tracer Diffusion Mechanism in Amorphous Solids

Hung

Kien

Hue

2011

Journal of Metallurgy

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Tracer diffusion in amorphous solid is studied by mean of n B -bubble statistic. The n B -bubble is defined as a group of atoms around a spherical void and large bubble that represents a structural defect which could be eliminated under thermal annealing. It was found that amorphous alloys such as Co x B 100−x (x = 90, 81.5 and 70) and Fe 80 P 20 suffer from a large number of vacancy bubbles which function like diffusion vehicle. The concentration of vacancy bubble weakly depends on temperature, but essentially on the relaxation degree of considered sample. The diffusion coefficient estimated for proposed mechanism via vacancy bubbles is in a reasonable agreement with experiment for actual amorphous alloys. The relaxation effect for tracer diffusion in amorphous alloys is interpreted by the elimination of vacancy bubbles under thermal annealing.

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“…It is widely accepted that the diffusion enhance in as-quenched sample of AMA is ascribed to the quasivacancies in super-saturation. Upon thermal annealing these vacancies are mobile and thus give rise to a contribution of selfdiffusion by exchanging their site with adjacent atoms [2,6,13]. On the other hand, molecular dynamic simulations [14,15,18] reveal the unstableness of vacancies or large interstices.…”

Section: Introductionmentioning

confidence: 99%

“…Diffusion in amorphous alloys (AMA) remains a fundamental open question for understanding many physical processes that occurred in disordered system and it is of interest for both Physics and Material Sciences [1][2][3][4][5][6][7][8][9][10]. In the present work we focus on some aspects of the vacancy-diffusion mechanism in AMA, since it has been debated for long times (see ref.…”

Section: Introductionmentioning

confidence: 99%