Following a recent investigation carried out at ID12, the measurement of magnetic susceptibility using XMCD at the U M4 and M5 edges yielded an observation of enhanced paramagnetism and lack of magnetic order in UO2 thin films (< 21nm) epitaxially grown on a series of perovskite substrates. Firstly, it is of interest to investigate if the enhancement of susceptibility at low-T is a function of film thickness. Additionally, it would be beneficial to gather data to determine the finite size effects and ultimately the critical thickness of AFM order in UO2 films. Both can be measured with XMCD at ID12. Samples for this experiment will be grown on the LSAT ((La,Sr)(Al,Ta)O3) perovskite substrate as this yielded UO2 samples with excellent crystalline quality.