Revisiting the phase transitions in BaxSr1-xTiO3 at low doping range (x≤0.1)

Ba2+ substituted SrTiO3, BaxSr1-xTiO3 (BST) at low doping range (x ≤ 0.1) is of particular interest for studying the phase transitions induced by a small amount of polar dopants in the paraelectric matrix SrTiO3. We have studied the crystal structure, dielectric and pyroelectric properties of BST (x ≤ 0.1) in this paper. It is revealed that a few of polar dopants Ba2+ in quantum paraelectric matrix SrTiO3, not only enhance the phase transitions of SrTiO3 around 18 K and 37 K, which are suppressed by the high quantum fluctuations in pure SrTiO3, but bring about “local ferroelectric symmetry breaking”. However, no structural transition related to the ferroelectric phase in the BST (x ≤ 0.1) at macroscopic scale.