Magnetoelasticity - magnetic structure interrelation – tetragonal MnPt system study

Magnetic materials represent an essential ingredient for the contemporary industry. Apart from common material parameters such as magnetocrystalline anisotropy, coercivity, or saturation magnetization, magnetoelastic behavior is vital for applications serving in various devices, e.g., in acoustic actuators, transducers, or sensors providing a desirable fast response and high efficiency with respect to applied magnetic field. Magnetoelastic properties have been studied for ferromagnetic 3d elements, or especially in high symmetry systems containing rare-earth elements to achieve higher values. Since, unlike for rare earth Laves phases, in the transition metals or alloys, these effects are very weak. Here, in contrast, we analyze the magnetoelastic behavior of antiferromagnetic tetragonal system MnPt, explaining the experimentally measured data based on the theoretical calculations and discussing the influence of the magnetic structure. Particularly, we inspect the origin of magnetocrystalline anisotropy energy, as well as the size and source of the isotropic and anisotropic parts of magnetoelastic (magnetostriction) coefficients.