Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
673212 | Thermochimica Acta | 2015 | 4 Pages |
•Thermal expansions of Bi0.8−xPrxBa0.2FeO3 (x ≤ 0.1) are studied by HT-XRD.•No phase decomposition and structural phase transition detected.•The unit cell thermal expansion and thermal expansion coefficients are positive.•The thermal expansion coefficients abnormal around the Néel temperature are observed.
At temperature range of 25–800 °C, in situ X-ray diffraction studies on Bi0.8−xPrxBa0.2FeO3 (x ≤ 0.1) ceramics are performed. The unit cell symmetry remains unchanged, while temperature dependence of lattice parameters and unit-cell volumes vary. There are no phase decomposition and structural phase transition detected in the system, which indicate that Pr, Ba co-doping may stabilize the structure of BiFeO3 ceramic. The unit cell thermal expansion and thermal expansion coefficients are positive. However, for sample with x = 0.1, i.e., Bi0.7Pr0.1Ba0.2FeO3, the unit cell structural stability decreases, and the thermal expansion coefficient increases. The thermal expansion coefficients abnormal around the Néel temperature are observed, which may suggest a possible antiferromagnetic–paramagnetic transition. It is probably the explanation for their low thermal expansion coefficient during the heating process.