We propose to investigate the temperature dependence of magnetic dead-layer thickness in amorphous ferromagnetic CoFeTaB films on Si and GaAs semiconductor substrates. Magnetic dead-layers, particularly in ferromagnetic films on GaAs, are important for hybrid spintronics applications. However, no previous investigations have studied the temperature dependence of the dead-layer thickness. In our low-Curie-temperature films, the magnetic deadlayer may also be important in understanding more exotic magnetic behaviour. Thin films exhibit behaviour characteristic of 2D magnetism, and the magnetic anisotropy induced by the interface with GaAs potentially produces novel anisotropic 2D behaviour. In order to understand the unconventional magnetic behaviour in these materials we propose here to conduct preliminary measurements of dead-layer thickness in thicker CoFeTaB films.