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@article{Mellan:2018:10.1103/PhysRevB.98.174116,
author = {Mellan, TA and Duff, AI and Finnis, MW},
doi = {10.1103/PhysRevB.98.174116},
journal = {Physical Review B},
title = {Spontaneous Frenkel pair formation in zirconium carbide},
url = {http://dx.doi.org/10.1103/PhysRevB.98.174116},
volume = {98},
year = {2018}
}

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TY  - JOUR
AB  - With density functional theory we have performed molecular dynamics simulations of ZrC which displayed spontaneous Frenkel pair formation at a temperature of 3200 K, some 500 K below the melting point. To understand this behaviour, rarely seen in equilibrium simulations, we quenched and examined a set of lattices containing a Frenkel pair. Five metastable structures were found, and their formation energies and electronic properties were studied. Their thermal generation was found to be facilitated by a reduction of between 0.7 and 1.5 eV in formation energy due to thermal expansion of the lattice. With input from a quasi-harmonic description of the defect free energy of formation, an ideal solution model was used to estimate lower bounds on their concentration as a function of temperature and stoichiometry. At 3000 K (0.81 of the melting temperature) their concentration was estimated to be 1.2% per mole in a stoichiometric crystal, and 0.3% per mole in a crystal with 10% per mole of constitutional vacancies. Their contribution to heat capacity, thermal expansion and bulk modulus was estimated.
AU  - Mellan,TA
AU  - Duff,AI
AU  - Finnis,MW
DO  - 10.1103/PhysRevB.98.174116
PY  - 2018///
SN  - 2469-9950
TI  - Spontaneous Frenkel pair formation in zirconium carbide
T2  - Physical Review B
UR  - http://dx.doi.org/10.1103/PhysRevB.98.174116
UR  - http://arxiv.org/abs/1809.03281v1
UR  - http://hdl.handle.net/10044/1/64344
VL  - 98
ER  -

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Professor Michael W. Finnis

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