Shweta Jagtap

Thick film NTC thermistor for wide range of temperature sensing

Purpose – Aims to focus on temperature sensors.Design/methodology/approach – Negative temperature co‐efficient thermistor powders of ternary Mn, Co, Ni oxide along with RuO2 synthesized at relatively moderates temperature (1,000°C). Thick film thermistor paste compositions were formulated by mixing the semiconducting oxide powder, glass frit and organic vehicle. The physico‐chemical analysis, viz. X‐ray diffraction, scanning electron microscopy and thermogravimetry and IR spectroscopy were carried out for the synthesized powder and the resultant thick films. The X‐ray analysis of the powders showed the cubic spinel structure. The electrical properties like thermistor constant, sensitivity index and activation energy of the thick film NTC thermistor were determined.Findings – The room temperature resistance is observed to range from 490 KΩ to 4.13 MΩ with thermistor constant ranging from 3,275 to 3,980 K, in the temperature range of 25‐300°C.Originality/value – Describes research work on temperature sensor...

Ruthenium dioxide doped manganite‐based NTC thermistors for low‐resistance applications

Purpose – The purpose of this paper is to study the properties of disc type negative temperature coefficient (NTC) thermistors based on the spinel system Mn‐Co‐Ni‐O with the doping of RuO2 for the low‐resistance applications.Design/methodology/approach – Emphasis was placed on the properties of ruthenium dioxide doped manganite spinel system for low‐resistance applications. The properties such as microstructure, X‐ray diffraction analysis and electrical properties are reported.Findings – The prepared NTC thermistor compositions revealed the room temperature resistance and thermistor constant in the range of 28‐2,950 Ω and 1,539‐3,428 K, respectively. Hence, the prepared NTC thermistors with low resistance and moderate sensitivity are suitable from an industrial applications point of view.Originality/value – The paper reports upon a synthesis procedure which is a straightforward preparation of highly densified ternary oxide (Mn‐Co‐No‐O) thermistors.

Synthesis, Characterization and Fabrication of NTC Thick Film Thermistor Using Lead Free Glass Frit

Thermistors are important and attractive in microelectronic and optoelectronic systems due to their unique thermoelectric properties and their applications in air flow sensor, IR detectors, temperature sensors etc. In the present study, mixed transition manganite semiconducting ceramics with spinel structures are used for the preparation of negative temperature co-efficient (NTC) ceramic thermistor. Here, we report the preparation of NTC powders by co-precipitation of chlorides of Mn, Co, Ni and its lead free thick film thermistors. The synthesized NTC powders as well as its thick films were characterized by TGA, XRD, and SEM. The prepared thick film thermistors showed thermistor constant () in the range 3,562-4,334 K over the temperature range of 25-250 oC.

Rod type cermet based NTC themo-resistive sensors

Environment friendly thick film NTC thermistors based on spinel-type Semiconducting electroceramics compositions based on oxides of (Mn, Co, Ni) were fabricated on cyclindrical/rod type alumina substrate. Prepared rod type NTC thermistors were characterized by X-ray diffraction, and Scanning electron microscopy with energy depressive Xray analysis. Rod thermistor samples showed compact and homogeneous microstructure. The electrical parameters such as device resistance, thermistor constant, ageing, thermal cycling, and humidity testing of the thermistors were determined.