Pulsed laser deposition of Fe thin films in UHV

Pulsed laser deposition has been used to grow oriented iron thin films in ultra high vacuum on a tungsten (110) buffer layer on a substrate of Al2O3 (<11(2)over bar 0>). Time-of-flight ion measurements were used to characterise the ablation plume in the fluence range 1.7-6.8 J cm(-2), where the ion fraction varied from 0.6 to 0.8 and the average ion energy varied from 120 to 140 eV. The 30 nm iron films were deposited at a fluence of 3.0 J cm(-2). In-situ optical reflectivity was used to monitor the film thickness. A substrate temperature of 650 degrees C was found to optimise the crystalline quality of the iron films. Both the tungsten and the iron grow with [110] normal to the substrate. Transverse Kerr effect measurements showed square hysteresis loops with a coercivity of 1.3 kA/m for the iron film grown at 650 degrees C.