Aging improvement in Cu-containing NTC ceramics prepared by co-precipitation method

Mn2.15Cu0.4Ni0.45O4 NTC ceramics were prepared by using co-precipitation and solid-state methods, their structure and properties were characterized by using scanning electron microscopy analysis, powder Xray diffraction, temperature dependent resistivity, and accelerated aging tests at 125 degrees C (aging temperature). Having similar resistivities before aging, the co-precipitation samples had lower relative resistance drifts (22.5%) as compared with the solid-state samples (39.5%) after aging for 800 h. Thus, co-precipitation could be an effective method to improve electrical stability of Mn-Ni-Cu oxide negative temperature coefficient ceramics. (C) 2013 Elsevier B.V. All rights reserved.