  Thin film alloys with perpendicular anisotropy were studied using Lorentz
Transmission Electron Microscopy (LTEM). This work focuses on the configuration
of domain walls and demonstrates the suitability and accuracy of LTEM for the
magnetic characterisation of perpendicular magnetic anisotropy materials. Thin
films of chemically ordered ($\unit{L1_0}$) FePd alloys were investigated by
micro-magnetic modelling and LTEM phase retrieval approach. The different
components of magnetization described by the modeling were studied on
experimental images and confirmed by LTEM contrast simulation. Furthermore,
quantitative measurements of magnetic induction inside the domain walls were
made by using an original method to separate the electrical and magnetical
contributions to the phase information. Irregularities were also observed along
the domain walls which could play a major role during the magnetization
processes.
