X-ray reflectivity and resonant anomalous X-ray reflectivity of neodymium and ytterbium adsorbed to alumina surfaces at pH 6.5

This data package consists of a series high-resolution X-ray reflectivity (XR) and resonant anomalous X-ray reflectivity (RAXR) measurements of neodymium and ytterbium adsorption to alumina (001) and (012) crystal surfaces. Also included are data for the same alumina crystal surfaces in a sodium chloride fluid free of rare earth elements. All samples were measured in contact with a fluid consisting of 10 mmol/L NaCl and 1 mmol/L MES buffer at pH 6.5. Neodymium or ytterbium were added in solutions made from their chlorides and had final concentrations of 500 µmol/L. All datasets are assigned codes to indicate the specific sample conditions, consisting of three components: (1) C or R to indicate the (001) or (012) surfaces, respectively; (2) 1 or 2 to indicate the specific crystal used in the measurements; (3) NaCl, Nd, or Yb to indicate if the experiments were REE-free (NaCl) or the specific REE present. The data are subdivided into a folder containing the XR data and a folder containing the RAXR data, with a subfolder for each specific data file.XR and RAXR data are provided in a 4-column format consisting of the L value, the X-ray energy in eV, the measured X-ray reflectivity, and the uncertainty in the X-ray reflectivity. L values are derived from reindexing the crystal structure to have the third Miller index, L, aligned along the surface normal direction. Q in Å-1 can be calculated from L by multiplying by 2×pi×c, where c is the lattice parameter along the surface normal direction. c = 12.9877 Å for alumina (001) and 6.9613 Å for alumina (012).<br>本数据集包含一系列针对氧化铝(001)与(012)晶面吸附钕、镱的高分辨率X射线反射（XR, X-ray reflectivity）及共振反常X射线反射（RAXR, resonant anomalous X-ray reflectivity）测量数据，同时包含不含稀土元素（rare earth elements, REE）的氯化钠流体体系下同种氧化铝晶面的测量数据。所有样品均在由10 mmol/L氯化钠与1 mmol/L MES缓冲液（MES buffer）组成、pH值为6.5的流体环境中完成测量。实验所用钕与镱以氯化物形式添加，溶液终浓度为500 µmol/L。所有数据集均配有编码以标识具体样品条件，编码包含三部分：(1) C或R，分别对应(001)与(0122)晶面；(2) 1或2，标识实验所用的具体晶体；(3) NaCl、Nd或Yb，分别代表实验体系不含稀土元素（REE）或对应添加的稀土元素种类。数据集分为两个主文件夹，分别存储XR数据与RAXR数据，每个具体数据文件对应一个子文件夹。XR与RAXR数据采用四列格式存储，依次为L值、X射线能量（单位：eV）、实测X射线反射率及反射率的不确定度。L值通过对晶体结构重新索引得到，将第三米勒指数（Miller index）L沿表面法线方向对齐。倒易空间矢量Q（单位：Å⁻¹）可通过将L值乘以2×π×c计算得到，其中c为沿表面法线方向的晶格参数：氧化铝(001)晶面的c值为12.9877 Å，氧化铝(012)晶面的c值为6.9613 Å。