Crystal structure and electronic states of Co and Gd ions in a Gd$_{0.4}$Sr$_{0.6}$CoO$_{2.85}$ single crystal

X-ray diffraction and X-ray absorption near edge structure (XANES) spectra have been measured at the Co $K$-edge and Gd $L_3$-edge in GdCoO$_3$ and Gd$_{0.4}$Sr$_{0.6}$CoO$_{2.85}$ cobaltites. The effect of Sr substitution on the crystal structure and electronic and magnetic states of Co$^{3+}$ ions in a Gd$_{0.4}$Sr$_{0.6}$CoO$_{2.85}$ single crystal has been analyzed. The XANES measurements at the Co $K$-edge have not showed a noticeable shift of the absorption edge with an increase in the concentration of Sr. This indicates that the effective valence of cobalt does not change. An increase in the intensity of absorption at the Gd $L_3$-edge is due to an increase in the degree of hybridization of the Gd$(5d)$ and O$(2p)$ states. The effect of hole doping on the magnetic properties results in the appearance of the ferromagnetic component and in a significant increase in the magnetic moment.