Itinerant-electron metamagnetic transition in LaFe₁₂B₆

LaFe₁₂B₆ (SrNi₁₂B₆-type) is an antiferromagnet with a low moment of 0.36 μ_B/Fe-atom in the ground state. The field-induced first-order transition takes place in a wide range of temperature including below and above the Néel temperature of 35 K. This transition results in a high moment of 1.6 μ_B/Fe-atom, being characteristics of the itinerant-electron metamagnetic transition. The critical magnetic field of the metamagnetic transition B_C increases with increasing temperature except for low temperature ranges, in which the kinetic arrest occurs. Above the arrested temperature, the sign of the temperature dependence of dB_C/dT is positive. The metamagnetic transition brings about large magnetocaloric effects, that is, a large negative value of the isothermal magnetic entropy change, ΔS_m, and a large positive value of the adiabatic temperature change, ΔT_ad.