Fig. 4: EFA analysis of La2TiFeO6.
a Entropy forming ability analysis of AIRSS results including different stoichiometries in the spectrum. The EFA reflexes the spectrum density and depends on the defect formation energies and hence on the chemical potentials of defects, μO and μLa. This is shown in the central panel where we report the EFA calculated in the energy window of stability for double perovskite structures (0-400 meV). This quantity reflects the amount of disorder that can emerge during material growth. The dashed white lines indicate the values of chemical potential, where the considered defects emerge in this energy window and hence contribute to the disorder. The four corner panels show how the EFA changes as La and O poor and rich conditions are considered. The green area highlights the energy window where perovskite structures are observed. b Volume distribution of AIRSS results including non-stoichiometric phases in La-poor and O-poor conditions. The blue circle highlights encapsulate the region with the highest state concentration responsible for the maximum of the EFA. All stoichiometric perovskite phases have comparable volumes of about 130 Å3. Extra oxygen causes a volume expansion, but phases with similar volumes can be obtained by removing 25% of La.
