Site occupation of doping La3+ cations and phase transition in Na0.5Bi0.5TiO3-BaTiO3 solid solution

Site occupation of doping La3+ cations and phase transition in Na0.5Bi0.5TiO3-BaTiO3 solid solution

Liu Li-Ying;Wang Ru-Zhi;Zhu Man-Kang;Hou Yu-Dong

【期刊名称】《中国物理：英文版》 【年(卷),期】2013(022)003

【摘要】The effects of La doping on the ferroelectric properties of 0.92Nao.5Bio.5TiO3-0.08BaTiO3 (NBT-BT) solid solution have been studied both experimentally and theoretically.The experimental results show that an abnormal ferro-toantiferroelectric phase transition is induced by La doping in NBT-BT.The first-principles calculations indicate that La3+ cations selectively substitute for the A site in NBT-BT as donors.Furthermore,the computed binding energy reveals that La cations is most likely to substitute Ba2+ or Na+,not Bi3+,at A site as donors in NBT-BT,as supported by our Raman spectra.The ferro-to-antiferroelectric phase transition of La-doped NBT-BT is believed to originate from the lattice aberrance and redistribution of valence electrons,thus strengthening the bonding of A-O,enhancing the hybridization between the A cation d orbital and O 2p orbital,and resulting in the deflection of the polar direction of NBT-BT lattice. 【总页数】6页(405-410) 【关键词】

【作者】Liu Li-Ying;Wang Ru-Zhi;Zhu Man-Kang;Hou Yu-Dong