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The elastic problem of a spherical core-shell particle with a truncated core is solved within the isotropic classical theory of elasticity. A transition to a Janus particle consisting of two unequal spherical segments with lattice mismatch is demonstrated. Elastic fields in the Janus particle are found and described in detail. The strain energy of the Janus particle in dependence on the interface coordinate is discussed.

The stress concentration and distribution around a triple-junction pore of three-fold symmetry in a polycrystalline ceramic material is considered. The perturbation method in the theory of plane elasticity is used to solve the problem of a nearly circular pore of three-fold symmetry under remote loading in the first approximation. The solution was specified to the uniaxial tension of convex and concave rounded triangular pores. The stress concentration on the pore surface and the stress distribution in vicinity of the pore along its symmetry axes are studied and discussed in detail. The numerical results, issued from the first-order approximation analytical solution, are compared with those of finite-element calculations.

The formation of copper pentagonal micropyramids (PMPs) with high (multiatomic) spiral growth steps, which are grown by electrocrystallization with mechanical activation of the cathode, is studied experimentally. A new spiral-layer growth mechanism for the formation of such PMP is proposed. It is shown that PMPs grow on flat pentagonal microcrystals (PMCs) formed initially and containing fivefold twins with one of the twin boundaries being inclined by the angle of 35°16’ to the {110}-type substrate crystallographic plane. Such crystal geometry causes an inclined growth step on the PMC surface. The preferential deposition of metal atoms on this step leads to the spiral-layer PMC growth and the formation of PMPs with a structure inherited from the PMCs.

A screw dislocation perpendicular to free surfaces and an interface in a two-phase plate, and a screw dislocation piercing a two-phase hollow sphere are considered. The analytical solutions of the boundary-value problems have been found for the first time with the help of the virtual defects technique. Elastic fields of the screw dislocation in the plate are presented in the form of integrals with Bessel functions. Elastic fields of the screw dislocation in the hollow sphere have the form of series with Legendre polynomials. Stress distributions in both of the considered geometries are plotted. The influence of the geometric parameters of the considered solids and the ratio of the shear moduli on the stresses is analyzed. The interaction of a screw dislocation with a parallel edge dislocation is discussed.

Formation of pores at foreign polytype boundaries in bulk SiC crystals is analyzed by using synchrotron radiation phase-sensitive radiography, optical and scanning electron microscopies and color photoluminescence. The studies have shown that the pore can either be a separate micropipe, or grow up to a certain length or occupy the whole facet of the inclusion depending on the inclusion distortion.

The ramification of micropipes is observed using scanning electron microscopy, optical microscopy, optical microscopy, and synchrotron x-ray radiography. It is shown that the ramification of micropipes in two smaller ones is possible only for micropipes with radii that exceed the equilibrium micropipe radius and is associated with a decrease in the total micropipe surface area.