Effects of external pressure on the narrow-gap semiconductor Ce3Cd2As6

Here we report the magnetic and electronic properties of recently discovered Ce3Cd2As6. At ambient pressure, Ce3Cd2As6 presents a semiconducting behavior with an activation gap of 74(1) meV. At 136 K, a sudden increase of the electrical resistivity and a peak in specific heat are consistent with a charge density wave transition. At low temperatures, antiferromagnetic order of the Ce3+ ions occurs below TN=4.0 K with a magnetic hard axis along the c axis and a Γ6=|±1/2) doublet ground state. The application of external pressure strongly suppresses the charge density wave order, which is completely suppressed above 0.8(1) GPa, and induces a metallic ground state. No evidence for superconductivity is detected above 2 K. Conversely, the antiferromagnetic state is favored by pressure, reaching a transition temperature of 5.3 K at 3.8(1) GPa. Notably, the resistivity anomaly characterizing the antiferromagnetic order changes with increasing pressure, indicating that two different magnetic phases might be present in Ce3Cd2As6 under pressure. This change in ordering appears to be associated to the crossing of the TCDW and TN lines.