A study of the reactivity of elemental Cr/Se/Te thin multilayers using X-ray reflectometry, in situ X-ray diffraction and X-ray absorption spectroscopy

作者：Behrens Malte; Tomforde Jan; May Enno; Kiebach Ragnar; Bensch Wolfgang^*; Haeussler Dietrich; Jaeger Wolfgang

来源：Journal of Solid State Chemistry, 2006, 179(11): 3330-3337.

DOI：10.1016/j.jssc.2006.06.024

• chromium chalcogenides
• modulated elemental reactants
• multilayer thin films
• anion substitution

The reactivity of [Cr/Se/Te] multilayers under annealing was investigated using X-ray reflectometry, in situ X-ray diffraction, X-ray absorption fine structure (XAFS) measurements and transmission electron microscopy. For all samples, interdiffusion was complete at temperatures between 100 and 300 degrees C depending on the repeating tri-layer thickness. A crystalline phase nucleated approximately 20 degrees C above the temperature where interdiffusion was finished. The first crystalline phase in a binary Cr/Te sample was layered CrTe3 nucleating at 230 degrees C. In ternary samples (Se:Te = 0.6-1.2), the low-temperature nucleation of such a layered CrQ(3) (Q = Se, Te) phase is suppressed and instead the phase Cr(2)Q(3) nucleates first. Interestingly, this phase decomposes around 500 degrees C into layered CrQ(3). In contrast, binary Cr/Se samples form stable amorphous alloys after interdiffusion and Cr3Se4 nucleates around 500 degrees C as the only crystalline phase. Evaluation of the XAFS data of annealed samples yield Se-Cr distances of 2.568(1) and 2.552(1) angstrom for Cr(2)Q(3) and CrQ(3), respectively. In the latter sample, higher coordination shells around Se are seen accounting for the Se-Te contacts in the structure.

• 出版日期2006-11