Dielectric and magnetic characteristics of LuFeMgO_4 ceramics

摘要

The magnetic and dielectric characteristics of LuFeMgO_4 ceramics were investigated together with the crystal structure. The present ceramics were refined as a rhombohedral structure in space group R3m, and antiferromagnetic with a Neel temperature of 27 K. The slim hysteresis loop measured at 10 K demonstrated weak ferromagnetic ordering in LuFeMgO_4 ceramics, which might be attributed to the canting angle in Fe moment. An obvious dielectric relaxation, which was well fitted by the modified Debye equation and Arrhenius law with an activation energy of 0.35 eV, was observed in the temperature range of 180-420 K. Moreover, the obtained dielectric constant was much larger than that reported previously. The dielectric relaxation could be strongly suppressed by oxygen annealing, indicating that oxygen vacancies played an important role in the dielectric response of LuFeMgO_4 ceramics.