在壳模型的基础上,通过分子动力学方法模拟了压强对Bi4Ti3O12(BIT)铁电相变行为的影响.为了提高模拟的准确性,在原有势参数的基础上增加了Ti-Ti短程相互作用势.计算得出了温度为300K时BIT单晶的铁电正交B2cb相在x方向和z方向的自发极化强度分别为39.4μC/cm2和0,与实验结果较好的吻合.然后模拟了压强对BIT相变行为的影响.模拟结果表明:BIT单晶在压强从-2 GPa到24 GPa范围内,经历了两次结构相变,分别发生在6 GPa和20GPa处.这种对称性的改变类似于在环境压力条件下温度导致BIT单晶对称性的改变.因而模拟结果为研究压强引起BIT的相变行为提供了理论依据.
参考文献
| [1] | Scott J F.Applications of modem ferroelectrics.Science,2007,315(5814):954-959. |
| [2] | Kimura T,Yoshimoto T,lida N,et al.Mechanism of grain orientation during hot-pressing of bismuth titanate.J.Am.Ceram.Soc.,1989,72(1):85-89. |
| [3] | Kingon A.Device physics:memories are made oF...Nature,1999,401(6754):658-659. |
| [4] | Hervoches C H,Lightfoot P.A variable-temperature powder neutron diffraction study of ferroelectric Bi4Ti3O12.Chem.Mater.,1999,11(11):3359-3364. |
| [5] | Hou J,Kumar R V,Qu Y,et al.Controlled synthesis of photoluminescent Bi4Ti3O12 nanoparticles from metal-organic polymeric precursor.J.Nanopart Res.,2010,12(2):563-571. |
| [6] | Cai M Q,Yin Z,Zhang M S,et al.Electronic structure of the ferroelectric-layered perovskite bismuth titanate by ab initio calculation within density functional theory.Cherm.Phys.Lett.,2004,399(1/2/3):89-93. |
| [7] | Cai M Q,Yin Z,Zhang M S,et al.First-principles study of ferroelectric and nonlinear optical property in bismuth titanate.Chem.Phys.Lett.,2005,401(4/5/6):405-409. |
| [8] | Hashimoto T,Moriwake H.Oxygen vacancy formation energy and its effect on spontaneous polarization in Bi4Ti3O12:a firstprinciples theoretical study.Phys.Rev.B,2008,78(9):092106-1-4. |
| [9] | Sani A,Hanfland M,Levy D.The equation of state of PbTiO3 up to 37 GPa:a synchrotron X-ray powder diffraction study.J.Phys.:Condens.Matter.,2002,14(44):10601-10604. |
| [10] | Kreisel J,Bouvier P,Maglione M,et al.High-pressure Raman investigation of the Pb-free relaxor BaTi0.65Zr0.35O3.Phys.Rev.B,2004,69(9):092104-1-4. |
| [11] | Sepliarsky M,Asthagiri A,Phillpot S R,et al.Atomic-level simulation of ferroelectricity in oxide materials.Solid State and Materials Science,2005,9(3):107-113. |
| [12] | Timte S,Stachiotti M G,Sepliarsky M,et al.Atomistic modelling of BaTiO3 based on first-principles calculations.J.Phys.:Condens.Matter,1999,11(48):9679-9690. |
| [13] | Timte S,Stachiotti M G.Phillpot S R,et al.Ferroelectric properties of Bax Sr1-xTiO3 solid solutions obtained by molecular dynamics simulation.J.Phys.:Condens.Matter,2004,16(20):3495-3506. |
| [14] | Gale J D.GULP:a computer program for the symmetry-adapted simulation of solids.J.Chem.Soc.,Faraday Trans.,1997,93(4):629-637. |
| [15] | Smith W,Yong C W,Rodger P M.DL_POLY:application to molecular simulation.Molecular Simulation,2002,28(5):385-471. |
| [16] | Pirovano C,Saiful Islam M,Vannier R N,et al.Modelling the crystal structures of aurivillius phases.Solid State lonics,2001,140(1/2):115-123. |
| [17] | Snedden A,Lightfoot P,Dinges T,et al.Defect and dopant properties of the aurivillius phase Bi4Ti3O12.Journal of Solid State Chemistry,2004,177(10):3660-3665. |
| [18] | Cummins S E,Cross L E.Electricai and optical properties of ferroelectric Bi4Ti3012 single crystals.J.Appl.Phys.,1968,39(5):2268-2274. |
| [19] | Noguchi Y,Goto T,Miyayama M.Ferroelectric distortion and electronic structure in Bi4Ti3O12.J.Electrocerarn,2008,21(1-4):49-54. |
| [20] | Kourouklis G A,Jayaraman A,Van Uitert L G.Pressure dependence of the Raman-active modes in Bi4Ti3O12.Materials Letters,1987,5(3):116-119. |
| [21] | Maczka M,Paraguassu W,Souza Filho A G,et al.Phononinstability-driven phase transitions in ferroelectric Bi2WO6:Eu3+:high-pressure Raman and photoluminescence studies.Phys.Rev.B,2008,77(9):094137-1-9. |
| [22] | Maczka M,Freire P T C,Luz-Lima C,et al.Pressure-induced phase transitions in ferroelectric Bi2MoO6-a Raman scattering study.J.Phys.:Condens.Matter,2010,22(1):015901-1-6. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%