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By the method of molecular dynamics simulation the structure of the interphase boundary (IB) fcc(001)/fcc(001) for the system 'crystalline half-sphere nanocrystal Ni - crystalline substrate Pd' with respect to the rotation angle of the nanocrystal (θ = 8°, 15°,20°,25°,30°) has been studied.
The Pd substrate was simulated in the form of a calculated cell containing 8 crystallographic (001) planes with 900 atoms in each plane. The crystalline nanocrystal Ni was simulated in the form of a half-sphere in the central part of the substrate surface, containing 597 or 5097 atoms and rotated by an θ angle with respect to the substrate. In choosing the angles for the initial orientation we proceeded from the non-monotonous dependence of the interphase boundary energy on θ for α < 0.9, which suggests the local minima for the special interphase boundaries (θ =θk) and the limiting value for the deviation from the parallel orientation of about 8°. The interaction between the atoms was described by the use of multiparticle potentials, calculated within the limits of the embedded atom method.
It has been shown the dimensional dependence for the nanocrystal rotation either to the parallel orientation or to the coincidence orientations on the IB, which are the nearest to the initial coincidence orientation. The deviation accommodation from θ= 0 and θ=θk for the large nanocrystals is performed by the primary and the secondary interphase dislocations, respectively.
The characteristic property of the IB atomic structure is that for the large misorientation angles (15° - 30°) during the process of its formation the atomic reconstructions are localized only in the crystal lattice with the higher parameter both in the system 'single-crystal Pd - nanocrystal Ni' and in the system 'single-crystal Ni - nanocrystal Pd'. Such a nature of the atomic reconstruction allows to avoid the approach of the atoms and the energy increase due to anharmonicity of the atomic interaction.The work was performed under the grant of the President of Russian Federation "Support of the Leading Scientific Schools", No.SS-7098.2006.3.
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