Structural, morphological and conducting properties of copper and nickel-substituted strontium manganite

Transition metals (copper and nickel) substituted SrMnO3 are synthesised by the solid-state reaction method. The substitution is expected to create oxygen vacancies in SrMnO3, increasing the hopping sites for ionic conduction. The prepared samples are characterised using various experimental techniques to investigate their structural, thermal, and conducting properties. X-ray diffraction confirmed the presence of secondary phases that decrease grain growth for both the substitution in SrMnO3-delta. The coefficient of thermal expansion is between 9 and 11 x 10-6 degrees C-1 in the temperature range of 200-1000 degrees C. An increase in the conductivity of similar to 4-5 orders is observed in all the samples at 600 degrees C compared to the conductivity at room temperature. The samples exhibit good thermal stability and conductivity in the intermediate temperature range (600 degrees C). Cu2+ substitution increased the sinterability contrary to Ni2+ substitution in SrMnO3.