Petkov Valeri, Trikalitis Pantelis N, Bozin Emil S, Billinge Simon J L, Vogt Thomas, Kanatzidis Mercouri G
Department of Physics and Astronomy and Center for Fundamental Materials Research, Michigan State University, East Lansing 48824, USA.
J Am Chem Soc. 2002 Aug 28;124(34):10157-62. doi: 10.1021/ja026143y.
A long-standing issue regarding the local and long-range structure of V(2)O(5)*nH(2)O xerogel has been successfully addressed. The full three-dimensional structure of the lamellar turbostratic V(2)O(5)*nH(2)O xerogel was determined by the atomic pair distribution function technique. We show that on the atomic scale the slabs of the xerogel can be described well as almost perfect pairs (i.e., bilayers) of single V(2)O(5) layers made of square pyramidal VO(5) units. These slabs are separated by water molecules and stack along the z-axis of a monoclinic unit cell (space group C2/m) with parameters a = 11.722(3) A, b = 3.570(3) A, c = 11.520(3) A, and beta = 88.65 degrees. The stacking sequence shows signatures of turbostratic disorder and a structural coherence limited to 50 A.
关于V₂O₅·nH₂O干凝胶的局部和长程结构这一长期存在的问题已得到成功解决。通过原子对分布函数技术确定了层状乱层结构的V₂O₅·nH₂O干凝胶的完整三维结构。我们表明，在原子尺度上，干凝胶的板层可以很好地描述为由四方锥VO₅单元构成的单个V₂O₅层的几乎完美的对（即双层）。这些板层被水分子隔开，并沿着单斜晶胞（空间群C2/m）的z轴堆叠，其参数为a = 11.722(3) Å，b = 3.570(3) Å，c = 11.520(3) Å，β = 88.65°。堆叠序列显示出乱层无序的特征以及限于50 Å的结构相干性。
