Effect of pressure on the electrical resistivity and magnetism in UPdSn

The electrical resistivity of a UPdSn single crystal exerted to various hydrostatic pressures was measured as a function of temperature and magnetic field. Clear anomalies in the temperature dependence of resistivity along the c-axis mark the magnetic phase transitions between paramagnetic and antiferromagnetic (AF) state at TN and the AF 1 -AF2 transition at T I .L arge negative magnetoresistance effects have been observed not only in the AF state as a result of the metamagnetic transition to canted structure ai B,, but also at temperatures far above TN. The latter result is attributed to the existence of AF correlations or short range AF ordering in the paramagnetic range. The value of TN increases with increasing applied pressure, whereas TI simultaneously decreases. It is also found that 13, decreases with increasing pressure. As a consequence, the stability range of the AF- 1 phase expands with applied pressure partially on account of the ground-state AF-2 phase