Metamagnetic Transitions in La _0.5 Pr _0.5 Mn _2 Si _2

La _0.5 Pr _0.5 Mn _2 Si _2 undergoes an antiferromagnetic−ferromagnetic transition at about 250 K ( -23 ^∘ C). This transition can also be induced by an external magnetic field leading to a metamagnetic transition. This can lead to a large change in the magnetic entropy, which is useful for magnetic cooling and studying the magnetocaloric effect. We investigated the details of the spin configuration as the magnetic ordering progresses from AF to FM by neutron diffraction techniques under magnetic fields up to 5 T and using spectral refining methods.