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MM: Fachverband Metall- und Materialphysik

MM 61: Liquid and Amorphous Metals V - Structure and structure formation

MM 61.4: Vortrag

Donnerstag, 3. April 2014, 16:30–16:45, IFW A

ASAXS on NiPB amorphous nanograined material — •Sören Gayer¹, Ulla Vainio¹, Vikram Raghuwanshi², Armin Hoell², Andreas Schreyer¹, and Jixiang Fang³ — ¹Helmholtz-Zentrum Geestacht, Geesthacht, Germany — ²Helmholtz-Zentrum Berlin, Berlin, Germany — ³Xi’an Jiaotong University, Xi’an, China

An exhaustive understanding of new materials includes a description of the internal structure. As for the class of amorphous nanograined metals, this structure includes inhomogeneities both in density and chemistry. They are produced by compressing nanometer-sized armorphous particles with high pressures. To investigate their structure (anomalous) small-angle X-ray scattering, (A)SAXS, is a good method, sensitive to density and, in the case of ASAXS, chemistry differences.

The nanoparticles for the investigated samples were created by chemical reduction of compounds containing Ni, P and B in solution. The then dried precipitates were compressed with pressures ranging from 0.5 to 4.0 GPa to form thin disks. Due to the chemical reduction, interfaces were already formed within the relatively large particles during their synthesis.

Measurements were performed at the ASAXS station (7T-MPW-SAXS) at the synchtrotron source BESSY II. The measured SAXS curves were fitted with different models to determine sizes and density differences of the substructures. The structural models were then tested with the Akaike information criterion to select the best of them.