Pulsed laser deposition of Mg thin films on Cu substrates for photocathode applications

Abstract

In this study, pulsed laser ablation of pure Mg targets (99.99%) using an XeCl excimer laser ( λ = 308 nm, τ = 30 ns) was used to grow Mg coatings on Cu substrates. A thin layer of Mg (100–200 nm) was deposited in UHV of 5 × 10 −6 Pa to ensure high purity. A second ultra-thin layer of MgO of 10–20 nm was deposited in oxygen at 10 −2 Pa pressure to protect the previous layer from atmospheric contamination. Measurements for determining the electron yield of the deposited samples under UV irradiation were performed on a diode structure in another UHV apparatus evacuated to 10 −6 Pa.