Structural and electrical properties of the sol-gel prepared Sr{sub 1-x}Er{sub x}SnO{sub 3-{delta}} compounds

Erbium-substituted strontium stannates, with Er content 0{<=}x{<=}0.09, have been prepared by sol-gel method. The solubility limit of Er was found to be about 3%. The influence of temperature and the duration of the calcination, on the confirmation of single phase of Er doped SrSnO{sub 3} were investigated by using X-ray powder diffraction. The distribution of Er{sup 3+} in the crystal structure has been studied. Rietveld refinement of the data revealed that the crystal structure of the representative compound (Sr{sub 0.97}Er{sub 0.03}SnO{sub 3-{delta}}) is orthorhombic perovskite (space group Pbnm). The cell dimensions are: a=5.7152(1) A, b=5.7092(1) A and c=8.0710(2) A. The IR spectroscopy measurements of the samples with x{<=}0.03 were done in a wavelength range 400-2000 cm{sup -1} and confirmed the observed tilting in the SnO{sub 6} octahedra. The transport properties in the system Sr{sub 1-x}Er{sub x}SnO{sub 3-{delta}}, x{<=}0.03, were investigated at high temperature. The Sr{sub 0.97}Er{sub 0.03}SnO{sub 3-{delta}} compound exhibits semiconductive behaviour and the electrical transport mechanism agrees with the non-adiabatic small polaron hopping model between nominal states Sn{sup 4+}/Sn{sup 2+} in the temperature ranges 350-525 and 525-693 K separately. - Graphical abstract: The Sr{sub 0.97}Er{sub 0.03}SnO{sub 3-{delta}} compound exhibits semiconductive behaviour and the electrical transport mechanism agrees with themore » non-adiabatic small polaron hopping model between nominal states Sn{sup 4+}/Sn{sup 2+}. Highlights: Black-Right-Pointing-Pointer Er showed a maximum solubility of 3 mol% in SrSnO{sub 3} perovskite at 1173 K. Black-Right-Pointing-Pointer SnO{sub 6} octahedra in Sr{sub 1-x}Er{sub x}SnO{sub 3-{delta}} are tilted. Black-Right-Pointing-Pointer The expansion of the cell parameters ascribed to the apparition of Sn{sup 2+} ions. Black-Right-Pointing-Pointer Transport mechanism in Sr{sub 0.97}Er{sub 0.03}SnO{sub 3-{delta}} agrees with the non-adiabatic small polaron hopping model.« less