Electronic transport minimum in SmCuAs2 at low temperatures and structural anomalies

Temperature dependent x-ray diffraction and electrical transport under pressure have been reported on SmCuAs2, which has been known to exhibit an unusual transport behaviour (a pronounced minimum much before long range magnetic order (Sampathkumaran et al., 2003 [6])) at low temperatures. The Néel temperature as well as the pronounced resistivity upturn observed before the onset of magnetic ordering is found to decrease sluggishly with pressure up to 15 kbar. External magnetic field has insignificant effect both at ambient and under pressure. Thus the anomalies are quite robust to applied pressure and magnetic field. Low temperature x-ray diffraction reveals no symmetry change, but the system exhibits lattice distortions along both a- and c-axes in the temperature region of interest, thereby suggesting that the resistivity anomalies could be associated with structural anomalies in this system.