Tenne D A, Turner P, Schmidt J D, Biegalski M, Li Y L, Chen L Q, Soukiassian A, Trolier-McKinstry S, Schlom D G, Xi X X, Fong D D, Fuoss P H, Eastman J A, Stephenson G B, Thompson C, Streiffer S K
Department of Physics, Boise State University, 1910 University Drive, Boise, Idaho 83725-1570, USA.
Phys Rev Lett. 2009 Oct 23;103(17):177601. doi: 10.1103/PhysRevLett.103.177601. Epub 2009 Oct 21.
We demonstrate the dramatic effect of film thickness on the ferroelectric phase transition temperature Tc in strained BaTiO3 films grown on SrTiO3 substrates. Using variable-temperature ultraviolet Raman spectroscopy enables measuring Tc in films as thin as 1.6 nm, and a film thickness variation from 1.6 to 10 nm leads to Tc tuning from 70 to about 925 K. Raman data are consistent with synchrotron x-ray scattering results, which indicate the presence of 180 degrees domains below Tc, and thermodynamic phase-field model calculations of Tc as a function of thickness.
我们展示了薄膜厚度对应变的生长在SrTiO₃衬底上的BaTiO₃薄膜中铁电相变温度Tc的显著影响。使用变温紫外拉曼光谱能够测量薄至1.6 nm的薄膜中的Tc，并且薄膜厚度从1.6 nm变化到10 nm会导致Tc从70 K调谐到约925 K。拉曼数据与同步加速器X射线散射结果一致，后者表明在Tc以下存在180度畴，以及Tc作为厚度函数的热力学相场模型计算结果。
