Altermagnets are a novel class of magnetic materials that combine properties associated with ferro- and antiferromagnetism: Like antiferromagnets, their magnetic moments compensate each other, resulting in no net magnetisation. At the same time, their particular crystal and magnetic symmetries can produce a spin-dependent electronic structure, a property that is attractive for future technologies based on controlling electron spins rather than only their charge. Experimentally demonstrating altermagnetism remains challenging, especially in electrically insulating materials where commonly used transport and photoemission techniques cannot easily be applied. During this internship, you will investigate a family of magnetic perovskite oxides, several of which have been predicted to be altermagnetic based on their crystal and magnetic symmetries. The project will combine theoretical calculations with state-of-the-art X-ray experiments: You will perform density functional theory (DFT) calculations at IMPMC, followed by multiplet calculations, to understand how the crystal and magnetic structure determines the expected signatures of altermagnetism. You will then have the opportunity to participate in an X-ray magnetic circular dichroism (XMCD) experiment at the BESSY II synchrotron at HZB in Berlin. By comparing theoretical predictions with experimental measurements, you will finally determine whether these materials really exhibit measurable signatures of altermagnetism.