resumo
Bi1-x Pr (x) FeO3 ceramics across the rhombohedral-orthorhombic phase boundary have been studied by X-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. The structural phase transitions in Bi1-x Pr (x) FeO3 driven by doping concentration and temperature are significantly different from those in BiFeO3 compounds doped with other rare-earth elements. The features of the structural transformations have been discussed based on the specific character of the chemical bonds associated with praseodymium ions. The detailed study of the crystal structure evolution clarified the ranges of both single-phase and phase coexistence regions at different temperatures and dopant concentrations. For x = 0.125, compound extraordinary three-phase coexistence state has been observed in a narrow temperature range at about 400 A degrees C. The results explicate driving forces of the structural transitions and elucidate the origin of the remarkable physical properties of BiFeO3-based compounds near the morphotropic phase boundary.
palavras-chave
EARTH-SUBSTITUTED BIFEO3; POWDER DIFFRACTION; THIN-FILMS; TRANSITIONS; BEHAVIOR
categoria
Materials Science
autores
Karpinsky, DV; Troyanchuk, IO; Sikolenko, V; Efimov, V; Efimova, E; Willinger, M; Salak, AN; Kholkin, AL
nossos autores
Grupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
agradecimentos
The authors would like to acknowledge the FCT (Grants SFRH/BPD/42506/2007, EXPL/CTM-NAN/1611/2013), RFFI (Grant 13-02-90903) and BRFFI (F014D-001). The work at CICECO was partly supported by the FCT Grant Pest-C/CTM/LA0011/013. Dr. Maria Celeste Azevedo is acknowledged for the DSC measurements.