Tuning oxygen content and distribution by substitution at Co site in 112 YBaCo₂O_5+δ: impact on transport and thermal expansion properties

Abstract

Polycrystalline “112” ordered oxygen deficient double perovskites YBaCo2−xMexO5+δ (Me = Fe, Cu, Ni) were synthesized by a glycerol-nitrate route with 0.0 ≤ x ≤ 0.7 for Me = Fe, 0.0 ≤ x ≤ 0.6 for Me = Cu and x = 0.1 for Me = Ni.

Defect formation in double perovskites PrBaCo2−xCuxO5+δ at elevated temperatures

“…One can see that copper substitution results in the increase of the elementary unit size. This change reflects replacement of Co 3+ for larger Cu 2+ cations [35], and is consistent with recent data on copper substituted barium yttrium double perovskite cobaltite [36]. The other effect of copper doping is related to the decrease in oxygen content (5 + δ) in the as-prepared samples from 5.77 to 5.52 for x = 0 and 0.5, respectively.…”

ReBaCo2-xMnxO5+δ (Re: rare earth element) layered perovskites for application as cathodes in Solid Oxide Fuel Cells

“…Such good transport properties results from highly-effective electron transfer occurring through the mentioned Zener mechanism [11,36]. It is generally known that substitution of cobalt with different 3d metals (such as iron or manganese) has generally negative impact on the total conductivity [35,37]. This behaviour can be explained taking the considered ReBaCo2-xMnxO5+δ group of materials as an example.…”

Layered Oxygen-Deficient Double Perovskites as Promising Cathode Materials for Solid Oxide Fuel Cells

“…A partial substitution of cobalt in Ln BaCo 2 O 5+δ perovskites by low-valence Ni- [ 129 , 130 , 131 ], Zn- [ 132 ], or Cu- [ 86 , 131 , 133 , 134 , 135 ] ions led to a slight increase intheir lattice constants [ 131 ] and a decrease in oxygen content (δ) [ 131 , 132 ], TEC [ 129 , 130 , 134 , 135 ], and electrical conductivity values [ 86 , 129 , 130 , 131 , 134 ]. In some cases, such a substitution improved the electrochemical performance of the derived cathode materials [ 129 , 130 , 132 , 134 ].…”

“…The effect of the partial substitution of cobalt with iron in layered perovskites of REE and barium and their A-site-deficient and A-site-substituted derivatives was intensively studied in a number of works [ 86 , 131 , 135 , 142 , 143 , 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , 158 ]. It was found that Fe-doping results in an increase of lattice constants [ 131 , 143 , 144 , 145 , 147 , 148 , 151 , 153 , 154 , 157 ] and oxygen contents [ 131 , 146 ]. Electrical conductivity of such Fe-doped cobaltites decreases with Fe-doping [ 143 , 145 , 146 , 147 , 153 , 154 , 157 ].…”

“…Electrical conductivity of such Fe-doped cobaltites decreases with Fe-doping [ 143 , 145 , 146 , 147 , 153 , 154 , 157 ]. TECs also decreased [ 143 , 147 , 153 ], though some works reported an inverse tendency [ 131 , 144 ]. The Fe-doping usually improved the electrochemical performance of the layered cobaltites as SOFCs cathodes, but, in a number of works, increased polarization resistances [ 144 , 145 ] or reduced power densities [ 142 , 144 ] were reported, showing that the final properties of materials depend on both chemical compositions of LODPs and the prehistory of their preparation.…”