CaTiO3 nano ceramic for NTCR thermistor based sensor application

Abstract

Abstract:It is possible to fabricate highly sensitive NTCR (negative temperature coefficient of resistance) thermistor using nano crystalline CaTiO 3 synthesized by high energy ball milling. Disc shaped green pellets were prepared and effects of sintering on the disc pellets were studied as thermistor by sintering the samples at 1000 ℃, 1100 ℃ and 1200 ℃. The as-prepared samples were characterized by X-ray diffraction (XRD), impedance analysis and electrical measurement. The resistivity of the prepared samples varies predictably with temperature: this makes them promising material for temperature sensor. The experimental results prove that nano crystalline CaTiO 3 ceramic is one kind of thermistor with exponential negative temperature coefficient of resistance in the temperature range of 300-500 ℃. The samples have the advantages of rapid response, high sensitivity and capability to withstand thermal surges over the temperature range of 300-500 ℃. Resistance-temperature characteristics are described by thermistor equation with thermistor constant around 4003 K to 10795 K and thermal coefficient of resistance α around 1%/℃ to 13%/℃. The activation energy is in the range of 0.34-0.93 eV. The observed thermistor parameters are found to be comparable with many of the known thermistor materials. This suggests that the electrical properties can be adjusted to desirable values by controlling the temperature parameter. The influence of fabrication process of disc thermistor and electrical properties are discussed. The study shows the potential of nano crystalline CaTiO 3 to act as an NTCR material for thermistor applications.

Relationship between Young’s Modulus and Planar Density of Unit Cell, Super Cells (2 × 2 × 2), Symmetry Cells of Perovskite (CaTiO3) Lattice

“…The XRD pattern of CaTiO 3 is presented in Figure 2 . The characteristic peaks of CaTiO 3 correspond to the report in Ref [ 22 ]. The crystal structure of CaTiO 3 is cubic, the atomic positions of Ti are at (000), Ca at ( ) and O at ( ), ( ), ( ).…”

Effect on Structural, Electrical and Temperature Sensing behavior of Neodymium Doped Bismuth Ferrite

“…The electrical resistance of samples Bi(1-x) Ndx FeO3[x=0.5,0.6,0.7 and 0.8] are determined at different temperatures. The exponential variation of resistance of the samples with different temperatures ranging from 175 0 C to 250 0 C confirms the NTCR behavior [46,47] of samples as shown in Fig. 9(a).…”

“…It is confirmed that α decreases with rising in thermistor constant β [49] as shown in Table 3. The sensitivity index (α) is generally described in percentage per degree centigrade (%/℃) [47].…”

Characterization of new negative temperature coefficient thermistors based on Zn–Ni–O system

“…For instance, Ma et al [12] reported that the resistivity drift for Ni 0. 6 [13][14][15][16][17]. One of the distinct advantages of the semiconductive oxides used for the NTC applications is that the room-temperature conductivity can be effectively adjusted by element doping and the related thermal-sensitive constants can also be improved by substituting suitable impurities [17][18][19][20].…”