Displacive Phase Transitions in and Strain Analysis of Fe-Doped CaTiO3 Perovskites at High Temperatures by Neutron Diffraction

Atomistic Study of a CaTiO3‐Based Mixed Conductor: Defects, Nanoscale Clusters, and Oxide‐Ion Migration

“…The supercell had an atomic content of Ca 20 Ti 16 Fe 4 O 58 , with the four Fe atoms and two O vacancies placed in the lowest-energy configuration described in Section 2.3. The structure was also optimized under constant pressure conditions, again resulting in good agreement with the experimental unit-cell parameters of the equivalent single orthorhombic cell (Table 8b) [54]. …”

“…Becerro and coworkers [18,53,54] have studied phase fields in Fe-doped compositions and reported that the temperature of these phase boundaries decreases with Fe content. For a membrane of CaTi 0.8 Fe 0.2 O 3-d with a working temperature of ca.…”

“…For this, a supercell (1 × 1 × 5 orthorhombic unit cells) of CaTi 0.8 Fe 0.2 O 3-d [54] was constructed, in space group P1, to avoid partial occupancies. The supercell had an atomic content of Ca 20 Ti 16 Fe 4 O 58 , with the four Fe atoms and two O vacancies placed in the lowest-energy configuration described in Section 2.3.…”

Structural and thermoelastic properties of CaTiO3 perovskite between 7K and 400K

“…The orthorhombic space group Cmcm had been proposed by Kennedy et al [2] for this intermediate phase, but this has been discredited by the most recent work of Yashima and Ali [4]. However there still remain unexplained lattice parameter anomalies that have been observed at the highest crystallographic resolution by powder neutron diffraction in CaTiO 3 [7], the Ca-rich end of the Ca 1−x Sr x TiO 3 solid solution [6], and the Ti-rich end of the perovskite -brownmillerite CaTi x Fe III 1−x O 3−x/2 solid solution [8]. With the exceptions of the neutron diffraction and elasticity studies of the Sr-rich end of the Ca x Sr 1−x TiO 3 solid solution [6,9], there have been disappointingly few low-temperature studies of the physical properties of the CaTiO 3 end member.…”

Effect of temperature on the electrical properties of nanocrystalline CaTi1−x Fe x O3−Δ perovskite

“…The transition and rare earth metal ion-doped perovskite materials (ABO 3 ) reveal unique structural, magnetic, and electronic characteristics. However, many of the physical and electrical properties of perovskites, such as the state of polarization, phase transitions, and structural changes are highly temperature sensitive [8][9][10].…”