MAGNETIC AND ELECTRICAL-PROPERTIES OF THE HEAVY-FERMION COMPOUND NPSN3

NpSn3 is an antiferromagnet below T(N) = 9.5 K with a low value of the ordered magnetic moment. From the values of the specific heat coeffic ient in the paramagnetic and ordered phases it can be presented as a m oderate heavy fermion. Our results of magnetization and Mossbauer effe ct confirm previous studies. Furthermore we present resistivity and si ngle crystal neutron diffraction experiments. The latter definitively confirms the type I antiferromagnetic structure which was up to now on ly suggested by Mossbauer spectroscopy. Results are discussed from bot h the band and the local 5f points of view.