First-principles thermodynamic calculations of diffusion characteristics of impurities in γ-iron

被引：5

作者：

Tsuru, T. ^{[1
]}

Kaji, Y. ^{[1
]}

机构：

[1] Japan Atom Energy Agcy, Nucl Sci & Engn Directorate, Tokai, Ibaraki 3191195, Japan

来源：

JOURNAL OF NUCLEAR MATERIALS | 2013年 / 442卷 / 1-3期

关键词：

CLUSTER EXPANSIONS; ENERGY; DYNAMICS; ALLOYS; POINTS;

D O I：

10.1016/j.jnucmat.2013.03.051

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Because solute impurities have an effect on embrittlement through segregation under irradiation, solute stability and the influence of irradiation on the diffusion characteristics of impurities become prominent due to several acceleration effects of high irradiance circumstances in irradiated materials. In this study, the diffusion characteristics of several impurities in non-magnetic fcc iron are investigated using first-principles density functional theory (DFT) calculations. In accordance with classical diffusion and transition state theories, we nonempirically evaluated the contribution to properties of the binding energy between vacancy and each impurity and the migration enthalpy. The migration energy was calculated using the nudged elastic band method with DFT. The vacancy formation energy, including the entropic contributions to free energies in gamma-iron, was evaluated by considering vibrational phonon frequencies based on frozen phonons employing the harmonic approximation for the lattice dynamics. Consequently, we confirmed that the binding energy between large-radius impurities and vacancies is larger than that with an equivalent size of the solvent element, and that the migration enthalpies of these impurities are quite small compared with self diffusion. This finding may indicate that the electronic binding states at the saddle point have a large influence on the migration of impurities. (C) 2013 Elsevier B. V. All rights reserved.

引用

页码：S684 / S687

页数：4

共 27 条

[1]

Bragg W. L., 1934, Proc. R. Soc. London, Ser. A, V145, P699, DOI DOI 10.1098/RSPA.1934.0132

[2] The effect of thermal agitation on atomic arrangement in alloys - II [J].

Bragg, WL ;

Williams, EJ .

PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL AND PHYSICAL SCIENCES, 1935, 151 (A874) :0540-0566

[3] Ab-initio based modeling of diffusion in dilute bcc Fe-Ni and Fe-Cr alloys and implications for radiation induced segregation [J].

Choudhury, S. ;

Barnard, L. ;

Tucker, J. D. ;

Allen, T. R. ;

Wirth, B. D. ;

Asta, M. ;

Morgan, D. .

JOURNAL OF NUCLEAR MATERIALS, 2011, 411 (1-3) :1-14

[4] ATOMIC SCREENING CONSTANTS FROM SCF FUNCTIONS .2. ATOMS WITH 37 TO 86 ELECTRONS [J].

CLEMENTI, E ;

RAIMONDI, DL ;

REINHARDT, WP .

JOURNAL OF CHEMICAL PHYSICS, 1967, 47 (04) :1300-+

[5] Ab initio calculations of defects in Fe and dilute Fe-Cu alloys -: art. no. 024103 [J].

Domain, C ;

Becquart, CS .

PHYSICAL REVIEW B, 2002, 65 (02) :1-14

[6] Stability and mobility of mono- and di-interstitials in α-Fe -: art. no. 175503 [J].

Fu, CC ;

Willaime, F ;

Ordejón, P .

PHYSICAL REVIEW LETTERS, 2004, 92 (17) :175503-1

[7] Vacancy-solute interactions in ferromagnetic and paramagnetic bcc iron: Ab initio calculations [J].

Gorbatov, O. I. ;

Korzhavyi, P. A. ;

Ruban, A. V. ;

Johansson, B. ;

Gornostyrev, Yu. N. .

JOURNAL OF NUCLEAR MATERIALS, 2011, 419 (1-3) :248-255

[8]

HAM JL, 1945, T AM SOC METAL, V35, P331

[9] A climbing image nudged elastic band method for finding saddle points and minimum energy paths [J].

Henkelman, G ;

Uberuaga, BP ;

Jónsson, H .

JOURNAL OF CHEMICAL PHYSICS, 2000, 113 (22) :9901-9904

[10] Current status and future R&D for reduced-activation ferritic/martensitic steels [J].

Hishinuma, A ;

Kohyama, A ;

Klueh, RL ;

Gelles, DS ;

Dietz, W ;

Ehrlich, K .

JOURNAL OF NUCLEAR MATERIALS, 1998, 258 :193-204

← 1 2 3 →