Phase Transitions and Magnetic Behavior in Ferromagnetic X₂YZ Heusler Alloys

The full Heusler alloy X 2 YZ, known for its relatively specific Curie temperature, is considered a promising candidate for diverse applications. Therefore, a theoretical study using mean‐field theory based on the Bogoliubov inequality for Gibbs free energy within the framework of the Ising model is essential for gaining a deeper understanding of the magnetic behavior of this material. In this work, the magnetic properties of an X 2 YZ full Heusler alloy are investigated, composed of mixed spins (2, 5/2). The study focused on the magnetic properties, where phase diagrams and magnetizations are obtained numerically. The model reveals both second‐ and first‐order phase‐transition lines, as well as tricritical and reentrant behaviors. The critical behavior is discussed and compared with previous studies on Ising systems.