Role of Excess Manganese in Formation of the Structure and Transport Properties of Manganite (Nd0.67Sr0.33)1–xMn1 + xO3 (x = 0, 0.2) Sintered at 1273–1473 K

Resumo

The Nd_0.67Sr_0.33MnO₃ manganite is a material promising for application as a cathode for medium-temperature solid oxide fuel elements. A high electrical conductivity of such a cathode is the parameter determining the efficiency of the operation of a fuel element. In this report, the effect of influence of excess manganese on the structure and the conductivity of manganite ceramics with compositions (Nd_0.67Sr_0.33)_1–xMn_{1 + x}O_{3± Δ} (x = 0, 0.2) sintered at temperatures 1273–1673 K is presented for the first time. The existence of 20% excess manganese in the initial manganite powder after sintering is shown to lead to that the conductivity of the obtained ceramics in the temperature range 823–1073 K is several times higher than the conductivity of the ceramics without excess manganese.