Laser-induced photoemission as a probe of slip band formation in single crystal and polycrystalline aluminum during uniaxial deformation

We report measurements of laser-induced photoelectron emission (LIPEE) from single crystal aluminum (99.999%) and high purity polycrystalline aluminum (>99.9%) during uniaxial tensile deformation. A 248-nm excimer laser (5-eV photon energy) was used as a light source. Deformation was performed on a tensile stage in ultra-high vacuum at an initial strain rate of 1 x 10-3 s-1. Photoelectron intensities are sensitive to changes in surface morphology accompanying deformation, including slip line and band formation. In the single crystal material, LIPEE intensity initially increases linearly with strain followed by a monotonically decreasing slope at larger strain. In the polycrystalline material, LIPEE intensities increase linearly with strain in two segments. Slip bands on the deformed surfaces were characterized by atomic force microscopy (AFM)