X-ray diffraction study of the phase transitions in Na0.5Bi0.5TiO3

First-principles study on the electronic and optical properties of Na0.5Bi0.5TiO3 lead-free piezoelectric crystal

“…Since NBT have been discovered by Smolensky et al, 1 it has attracted extensively attention as a promising environmental friendly lead-free ferroelectric material due to its possible applicability to electromechanical actuators, sensor, and transducers. 2 Also the NBT has a very peculiar sequence of phase transitions 3,4 from the cubic ͑Pm3m͒ at the temperature above 813 K, to the tetragonal ͑P4bm͒ in the range of 783-813 K, and then to the rhombohedral ͑R3c͒ structure at the temperature below 517 K, which shows unusual dielectric and ferroelectric properties. [3][4][5] In the ferroelectric phase, the NBT ceramic has a large remanent polarization of P r =38 C / cm 2 as well as a large coercive field of E c =73 kV/ cm at room temperature.…”

Observation of partially incoherent ⟨110⟩ boundaries between polar nanodomains in Na1/2Bi1/2TiO3 single crystals

“…6 It is believed that NBT undergoes a phase transition sequence of high-temperature cubic ͑C͒ → paraelectric tetragonal ͑T͒ → FE rhombohedral ͑R͒ at temperatures of 520°C and 250°C, respectively. [7][8][9][10][11][12][13][14] The T phase is ferroelastic, and there is no characteristic dielectric anomaly at the C → T transition. 15,16 Controversy remains concerning the T → R transition.…”

Hierarchical domains in Na1/2Bi1/2TiO3 single crystals: Ferroelectric phase transformations within the geometrical restrictions of a ferroelastic inheritance

“…2,4 In fact, longitudinal piezoelectric constants of d 33 Ϸ 500 pC/ N have been reported both under large amplitude drive in the -E response 2 and more recently under weak-field drive using a Berlincourttype meter. 4 The phase transformational sequence on cooling for NBT has been reported to be cubic͑C͒ → tetragonal͑T͒ → rhombohedral͑R͒: [5][6][7][8][9] with phase transition temperatures of about 520°C and 260°C, respectively. Interestingly, no distinct structural changes associated with the ferroelectric transformation have been reported at the maximum in the dielectric constant T max = 330°C.…”