Terahertz emission amplitude-based 2D mapping of the Fe thickness profile in Fe/Pt spintronic heterostructure

We demonstrate the feasibility of mapping metallic layer thickness profile in 2 dimension based on the amplitude of the terahertz emission of a large area spintronic heterostructure. A Fe/Pt bilayer was deposited on glass substrate such that a 100 mm diameter circular space was covered with 4 nm Pt throughout and with a gradient of 0.5 nm to 7 nm thick Fe by magnetron sputtering. The Fe thickness dependence of the spintronic THz emission is clearly observed in just one sample by two-dimensional amplitude mapping.