NTC Thermistors of Y-Al-Mn-Fe-Ni-Cr-O Ceramics for Wide Temperature Range Measurement

Abstract

NTC thermistors of Y-Al-Mn-Fe-Ni-Cr-O systems were fabricated by using normal ceramic processing for wide temperature range measurement. Pt-Rh alloy as electrodes was inserted into the body during the forming process to increase the reliability of high temperature and to decrease the contact resistance. The properties were analyzed by XRD, SEM and resistance measurement. There are no distinct XRD patterns between Y 0.2 Al 0.1 Mn 0.27 Fe 0.16 Ni 0.27 O x and Y 0.2 Al 0.1 Mn 0.264 Fe 0.16 Ni 0.264 Cr 0.012 O x because of too small content of Cr 2 O 3 , as a dopant, to make peak difference or new phases within the XRD resolution. SEM images and resistance behaviors show the different properties. With the addition of Cr 2 O 3 as a dopant, the crystallinity and the grain size were decreased and increased, respectively. The resistance behaviors were similar but the values are low with Cr 2 O 3. The specimens show the straight line relationship between the electrical resistivity and the temperature over a wide temperature range, indicating NTC thermistor characteristics.

Fabrication, Characterization and Comparison of Nanocrystalline NiMn2O4 and NiZn0.2Mn1.8O4 NTCR Ceramic Thermistor Powders

“…NiMn2O4 ceramic thermistor material can be synthesized in the miniaturized form using different fabrication techniques. Some of the methods are solid state reaction followed by successive heat treatments and solution method [10][11][12][13][14][15][16]. Solid state reaction technique is a very simple and economical technique but it takes a long time, results in impure materials and it consumes huge energy.…”