Comparison of Thermal Expansion Coefficient in Ln_0.6Sr_0.4Co_0.2M_0.8O_3−δ (Ln=La,Nd,Sm and M=Fe,Ni,Mn) as Cathode Materials for Solid Oxide Fuel Cell

In this study, thermal expansion coefficient variation of ln_0.6sr_0.4co_0.2m_0.8o_3−δ (ln=la,nd,sm and m= fe,ni,mn) perovskite oxide were evalouated. different compounds were prepared and thermal expansion coefficient were meseaured in different temperature by means of dilatometer analysis. structural parameters of compounds were determined by x-ray diffraction and field emission scanning electron microscopy (fe-sem) was used for the morphological study. using nd^3+ instead of la^3+ led to tilting of the bo6 octahedra, phase transition from rhombohedral to the orthorhombic. experimental results showed tec decreases favorably with substitution of nd^3+ and mn^3+ ions in the lattice.