The scanning electron microscopy (SEM) of the surface and the energy-dispersive X-ray (EDX) microanalysis were performed in the microscopes Nova NanoSEM 200 (FEI Company, USA) and REM-106I (SELMI, Ukraine). The X-ray diffraction (XRD) was studied in the filtered CuKa
(l=1.5406˚A) emission using the diffractometer PANalytical Empyrean. The phases were identified using X’Pert Highscore plus and ICDD PDF-2 data.