Effects of cation substitution on thermal expansion and electrical properties of lanthanum chromites

Synthesis and characterization of doped LaCrO3 perovskite prepared by EDTA–citrate complexing method

“…It has been found in our previous investigation that a small amount of substitution of Ni and Co for Cr could significantly increase the sinterability of La 0.85 Sr 0.15 CrO 3 [4]. Moreover, the investigation also revealed the co-doped composition, i.e., La 0.85 Sr 0.15 Cr 0.95 Ni 0.02 Co 0.02 O 3 , exhibited thermal expansion coefficients (TECs) matching that of SOFC electrolyte, maintaining high conductivity as well.…”

“…It is commonly known that LaCrO 3 is very difficult to sinter densely in air. It has been found that partially substituting La with alkaline metal ions, Ca or Sr, and Cr with transitional metal ions, Cu, Ni or Co, is beneficial to increase its sinterability and electrical conductivity [4]. And glass additives are generally used to reduce the sintering temperature of LaCrO 3 ceramics [5][6].…”

Electrical conduction behaviors of isovalent and acceptor dopants on B site of (La0.8Ca0.2)CrO3−δ perovskites

“…From the defect chemical reactions, Eqs. (7) and (12)- (14), it is assumed that the compensation mechanism completely dominated by electrical compensation and the concentration of electron hole should to be 0.2 + u at high oxygen activity. But in reality the electrical conductivities in air significantly varied with the kind of dopant.…”

“…However, there are several problems associated with these perovskite materials: (i) poor sinterability in air due to the volatilization of Cr, (ii) insufficiently high electrical conductivity, and (iii) mismatching of the thermal expansion coefficients (TECs) with other SOFC components. To reduce the previously mentioned disadvantages, some researchers have studied this material by substituting alkaline earth metal ions or transition metal ions at the La and Cr sites, respectively [10][11][12][13][14]. In previous works, there have been many investigations on the effects of crystal structure, microstructure, and electrical conductivity behaviors for ionic substitutions for the A sites and B sites behavior.…”

Development of lanthanum chromites-based materials for solid oxide fuel cell interconnects

“…Thus, the Sr concentration must be optimized and, moreover, the multiple doping studies can contribute for the stabilization of the properties of these lanthanum chromite-based ceramics. The additional doping with Mg resulted in the best densification condition (LCSCM system), although the synergetic action mechanism is not yet clear [17,18]. In fact, in mono-doped systems, Ca-doped LaCrO 3 expands more than Sr-doped LaCrO 3 does, because of greater ionic size difference between Ca and La than between Sr and La, contributing, in the second case, to the stability and densification of the ceramic body [6].…”