Roelsgaard Martin, Dippel Ann-Christin, Borup Kasper Andersen, Nielsen Ida Gjerlevsen, Broge Nils Lau Nyborg, Röh Jan Torben, Gutowski Olof, Iversen Bo Brummerstedt
Center for Materials Crystallography, Department of Chemistry, Aarhus University, Aarhus, Denmark.
PETRA III, Deutsches Elektronen-Synchrotron, DESY, Hamburg, Germany.
IUCrJ. 2019 Feb 23;6(Pt 2):299-304. doi: 10.1107/S2052252519001192. eCollection 2019 Mar 1.
Characterization of local order in thin films is challenging with pair distribution function (PDF) analysis because of the minute mass of the scattering material. Here, it is demonstrated that reliable high-energy grazing-incidence total X-ray scattering data can be obtained during thin-film deposition by radio-frequency magnetron sputtering. A benchmark system of Pt was investigated in a novel sputtering chamber mounted on beamline P07-EH2 at the PETRA III synchrotron. Robust and high-quality PDFs can be obtained from films as thin as 3 nm and atomistic modelling of the PDFs with a time resolution of 0.5 s is possible. In this way, it was found that a polycrystalline Pt thin film deposits with random orientation at 8 W and 2 × 10 mbar at room temperature. From the PDF it was found that the coherent-scattering domains grow with time. While the first layers are formed with a small tensile strain this relaxes towards the bulk value with increasing film thickness.
由于散射材料的质量极小，利用对分布函数（PDF）分析来表征薄膜中的局部有序性具有挑战性。在此，证明了通过射频磁控溅射在薄膜沉积过程中可以获得可靠的高能掠入射全X射线散射数据。在安装于PETRA III同步加速器的P07-EH2光束线上的新型溅射室中研究了Pt的基准系统。对于厚度仅为3 nm的薄膜也能够获得稳健且高质量的PDF，并且可以对PDF进行时间分辨率为0.5 s的原子建模。通过这种方式，发现在室温下以8 W和2×10 mbar沉积的多晶Pt薄膜具有随机取向。从PDF中发现，相干散射域随时间增长。虽然第一层形成时具有较小的拉伸应变，但随着膜厚度增加，该应变向体相值弛豫。
