Fig. 3: Resistive hotspot effect in pulsed direct current (PDC) process.
From: High-surface-area corundum nanoparticles by resistive hotspot-induced phase transformation
a X-ray diffraction (XRD) patterns of γ-Al2O3/CB with different mass ratios after the same PDC process. The marks are γ-Al2O3 (square), δʹ-Al2O3 (triangle), and α-Al2O3 (dot). The numbers are the mass ratio of γ-Al2O3 to carbon black (CB). b Phase mass ratios of the product after PDC process varied with volume fraction of γ-Al2O3, f(γ-Al2O3). The blue region denotes the pure α-phase at f = 0.73. c Conductivities and temperatures varied with f(γ-Al2O3). The blue region denotes the pure α-phase at f = 0.73. d–f Simulated current density maps of the sample during PDC with different γ-Al2O3 volume fractions of d f = 0.41, e f = 0.73, and f f = 0.78. The separated balls are γ-Al2O3 NPs and the continuous phase is CB. The color bars show the current density values.
