Effect of Internal Pressure on Charge-Ordered Rare Earth Manganates

Performance of (Ln0.5M0.5)FeO3-δ Perovskites as Cathode for SOFCs.: Effect of Mean Radious of the A site Cations

“…Additionally, bond angles increase with <r A > due to the reduction of the distortions of FeO 6 octahedra (increase of the symmetry), with increasing mean ionic radius. This trend has also been observed in other studies for perovskite compounds (24)(25)(26). Scanning electron microscopy (SEM) images of the sintered pellets are shown in Figure 3.…”

Distinction between Two Types of Charge-Ordered States in the Rare Earth Manganates,Ln0.5A0.5MnO3, Based on Chemical Melting

“…. These changes are in a direction opposite to that of external pressure or substitution by large A-site cations (6,7). Substitution of Al> in place of Mn> appears to have a negative pressure effect.…”

Impact of Jahn-Teller active Mn3+on strain effects and phase transitions in Sr0.65PrTan1, Kennedy2, Zhou3 et al. 2012Phys. Rev. B264120View full textAdd to dashboardCite

“…[4][5][6] An important feature of the mixed valence Mn 3+ /Mn 4+ manganates is the long-range orbital ordering that arises as a consequence of a Jahn-Teller (JT) type distortion of the formally Mn 3+ cations. It is generally accepted that replacing the trivalent lanthanide cation with a divalent alkaline earth cation introduces a mixed valence Mn 3+ and Mn 4+ array [7][8][9] where the charge can hop from Mn to Mn via the bridging oxygen anions. A consequence of the relatively large difference in the size of the Mn 3+ and Mn 4+ cations (ionic radii of 0.645 vs 0.53Å, respectively, in a six-coordinate geometry 10 ), together with the JT distortion, is that such a substitution is likely to introduce strains into the lattice.…”