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 dead-layer 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. Following our preliminary measurements on thicker CoFeTaB films, we plan to study thinner, quasi-2D, films in order to understand the unconventional and exotic magnetic behaviour in these materials.