Magnetic and electrical properties of NpSb2, NpTe2.0 and NpTe1.8

Abstract The magnetic and electrical properties of NpSb 2 , NpTe 2.0 and NpTe 1.8 were studied by magnetization and electrical resistivity measurements. NpSb 2 is ferromagnetic below T c = 45 K , but the magnetic structure is probably not simply collinear. NpTe 2.0 and NpTe 1.8 remain paramagnetic down to 4.2 K. The effective moment for all three compounds is in good agreement with the value calculated for Np 3+ in the intermediate coupling sheme. NpSb 2 is semimetallic ( ϱ 300 = 0.0264 Ω cm ) and the resistivity curve displays a broad anomaly around the magnetic transition temperature. NpTe 2.0 and NpTe 1.8 are closer to a semiconducting behaviour, the resistivity being 3 to 4 orders of magnitude larger at 4.2 K.