Magnetic properties of doped GdI2

Motivated by the recent experimental studies on layered ferromagnetic metallic system GdI₂ and its doped variant GdI₂H_x we develop a model to understand their ground state magnetic phase diagram. Based on first principle electronic structure calculations we write down a phenomenological model and solve it under certain approximations to obtain the ground state energy. In the process we work out the phase diagram of the correlated double exchange model on a triangular lattice for the specific band structure at hand.