On the lateral crystal growth of laser irradiated NiTi thin films

This letter demonstrates the ability to induce laterally grown, large-aspect crystals via pulsed, melt-mediated laser crystallization in NiTi thin films. Sputter-deposited 200 nm NiTi films were pulse irradiated utilizing a homogenized 308 nm excimer beam over a series of varying incident laser energy densities. Solidification occurred via two distinct pathways: nucleation and growth occurred away from the boundary of irradiation, while lateral growth of unmelted seeds into the undercooled melt developed at the boundary of irradiation. The potential for exploiting this technique to produce rolling direction texture for anisotropic properties is also discussed.