A local structure change of bulk Pd40Ni40P20 glass during full relaxation

Abstract The change in the amorphous structure of bulk Pd 40 Ni 40 P 20 glass during structural relaxation was examined by an anomalous X-ray scattering (AXS) experiment with energies near the Ni K-absorption edge. It was confirmed by differential scanning calorimetry that the sample reached a meta-stable state (a fully relaxed state) with an equilibrium free volume concentration after annealing for about 1 × 10 4 s at 563 K and 4 × 10 4 s at 557 K just below the glass transition temperature T g = 567 K. The structural changes on the progression toward a fully relaxed state were examined in samples annealed for 1 × 10 3 and 2 × 10 4 s at 563 K (glass A), and for 3.2 × 10 3 , 1 × 10 4 and 7 × 10 4 s at 557 K (glass B). The structural analysis revealed that the coordination number of Ni–Ni like atom pairs increased with annealing time and that of Ni–Pd, unlike atom pairs, decreased. Meanwhile, the coordination number N PNi of P–Ni atom pairs and the nearest neighbor distance r PNi did not show a remarkable variation. However, prolonged annealing of 7 × 10 4 s at 557 K induced a remarkable change in N PNi and r PNi .