Metamagnetic transition to poor conductor in BaVS₃

High-field magnetization measurements on BaVS₃ revealed a metamagnetic transition at B < B_M ≃ 50 T to a newly identified field-induced ferromagnetic phase, which bears the magnetic moment of ∼0.4 μ_B/V, approximately half of the saturation magnetization expected for S = 1/2. The transition is associated with an essential change in the electronic state to a poor conductor, where the gapped A_1g band remains open and only the poor conductivity of nearly localized E_g electrons is recovered by the field. Based on the magnetization results, a field-temperature phase diagram is proposed for BaVS₃.