Why Pb(B,B')O3 Perovskites Disorder at Lower Temperatures than Ba(B,B')O3 Perovskites
Benjamin P. Burton, Eric J. Cockayne
Fully relaxed, planewave pseudopotential calculations of total energies were performed for three ordered perovskite related supercells in each of the eight different stoichiometries of A(B1/3B'2/3)O3; A=Pb, Ba and B=Zn, Mg and B' = Nb, Ta; and the four stoichiometries of A (Sc1/2B'1/2)O3. A Striking difference between the Pb(B1/3B'2/3)O3 systems and their Ba-counterparts is that the differences in total energies for Pb-systems span ranges that are roughly an order of magnitude smaller than those for the corresponding Ba-systems. This indicates much lower energetic barriers to disordering of B - site cations in the Pb-systems, consistent with experiments. We explain this trend as a consequence of enhanced Pb - O bonding to underbonded oxygens in B2. - O - B2. environments.
Physical Review B (Condensed Matter and Materials Physics)
and Cockayne, E.
Why Pb(B,B')O<sub>3</sub> Perovskites Disorder at Lower Temperatures than Ba(B,B')O<sub>3</sub> Perovskites, Physical Review B (Condensed Matter and Materials Physics), [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=850295
(Accessed December 3, 2023)