EFFECT OF SUBSTITUTIONS OF SUPER-STOICHIOMETRIC MANGANESE WITH IONS OF TRANSITION METALS ON THE STRUCTURE AND THE PROPERTIES OF La<sub>0.6</sub>Sr<sub>0.2</sub>Mn<sub>1.2-x</sub>B<sub>x</sub>O<sub>3</sub> (B - Cr, Fe, Co, Ni; x = 0.1, 0.2)
Using X-ray structural analysis, resistive, magnetic (χ<sub>ас</sub>, NMR <sup>55</sup>Mn) and magnetoresistive methods, regularities of the effect of substitutions of super-stoichiometric manganese with ions of transition 3d-metals on the structure and the properties of the La<sub>0.6</sub>Sr<sub>0.2</sub>Mn<sub>1.2-x</sub>B<sub>x</sub>O<sub>3</sub> (B - Cr, Fe, Co, Ni; x = 0.1, 0.2) manganito-perofskites are established. It is shown that the changes of the parameter of rhombohedral lattice correlate to ion radius of the substituting B-ions and T<sub>C</sub> and magnetic inhomogeneity are related to the magnetic moment. We have observed two types of magneto-resistive effect: the first one occurs near the temperatures of phase transitions T<sub>ms</sub> and T<sub>C</sub> being caused by the scattering of charge carriers at intercrystalline nano-structure inhomogeneities, the second type is realized within the low-temperature area and determined by tunneling at meso-structure intercrystalline boundaries. The influence of the substituting 3d-ions on the properties and the resonance frequency of NMR <sup>55</sup>Mn spectra is explained by the weakening of exchange interactions between manganese ions Mn<sup>3+</sup> ↔ Mn<sup>4+</sup> and the change of the ration of Mn<sup>3+</sup>/Mn<sup>4+</sup>.