Thermistor Applications Research Articles

Review on the synthesis routes of nickel manganite – a potential material for thermistor applications

Review on the synthesis routes of nickel manganite – a potential material for thermistor applications

Unveiling the potential of a novel inorganic perovskite for NTC thermistor and energy-storage applications

Inorganic perovskite-oriented materials are renowned for their multifunctional characteristics, making them candidates for various advanced applications. This study focuses on the synthesis and characterization of a novel inorganic perovskite material, (Ni0.5Sm0.5FeO3)0.5(BaTiO3)0.5, prepared via the cost-effective solid-state reaction method. Detailed structural and microstructural analyses were conducted to determine phase formation and grain size effects. Rietveld analysis was employed to identify the crystallographic phases, while field emission scanning electron microscopy (FE-SEM) provided insights into the sample’s morphology. FTIR and RAMAN spectroscopy were used to investigate the vibrational modes of the material. The dielectric properties and electrical characteristics were measured across a range of frequencies and temperatures using an impedance analyzer. The material’s potential for energy storage and NTC-type thermistor applications was evaluated through its temperature coefficient of resistance (TCR) and thermistor constant (β) analysis. Additionally, the ferromagnetic property was assessed through M−H hysteresis loop analysis, highlighting the material’s multifunctional capabilities.

Important comments on the paper “Studies of structural, dielectric, and electrical properties of polycrystalline barium bismuth tungstate for thermistor application” by S.S. Hota et al., and published in Inorganic Chemistry Communications 153 (2023) 110785

My comments concern the serious errors in the crystallographic part of the commented paper. Authors have proposed that their sample presents a new crystal with the supposed chemical formula Ba3Bi2WO9. However, the correct analysis shows that the studied sample is a mixture of at least two compounds, Ba3W2O9 and Ba3WO6. As a result, the subsequent data on physical properties of the sample may be without a scientific value.

Doublet doped titanate ferroelectric system for capacitors and NTC thermistor applications

A simple negative temperature coefficient (NTC) thermistor Ba0.85Sr0.15Ti0.85Zr0.15O3 system is elaborated using a conventional solid-state reaction route. The structural analysis confirms that the elaborated pseudo-cubic system, which is indexed in the P4mm space group, exhibits one single phase. The dielectric properties and the electrical resistivity data are investigated over a large temperature range from 413 K to 673 K. In this temperature interval, the Steinhart–Hart equations are employed to confirm that Ba0.85Sr0.15Ti0.85Zr0.15O3 is a promising system for sensor application. Accordingly, the thermistor constant (β=10154 K), the sensitivity factor (-5.5 %/K≤α≤-2 %/K), the activation energy (Ea=0.875 eV), and the stability factor (SF=2.27) parameters are calculated to approve that Ba0.85Sr0.15Ti0.85Zr0.15O3 exhibits an NTC-thermistor behavior. The temperature dependence of the electrical resistivity confirms that Ba0.85Sr0.15Ti0.85Zr0.15O3 reveals a semiconductor behavior. The dielectric investigation shows that Ba0.85Sr0.15Ti0.85Zr0.15O3 exhibits a motivating dielectric properties (elevated dielectric constant value (105<ε’<106) and low dielectric losses (mostly < 0.007) with almost frequency independence between 20 Hz to 500 kHz). The colossal dielectric response of Ba0.85Sr0.15Ti0.85Zr0.15O3 is attributed to the internal barrier layer capacitor (IBLC) and the surface barrier layer capacitor (SBLC) effects. Such response suggests the suitability of Ba0.85Sr0.15Ti0.85Zr0.15O3 ceramic for high temperature capacitor applications.

Enhanced thermistor performance of LaCrO3 through high-entropy strategy

Lanthanum chromite (LaCrO3) based perovskites are crucial in advanced electronics for their stability, but efforts to enhance their density and structural stability remain vastly lacking. Here, we introduced high-entropy concept to enhance the microstructure and electrical properties of LaCrO3 for thermistor applications. The obtained La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3-δ and (La0.2Nd0.2Sm0.2Gd0.2Y0.2)(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3-δ ceramics showed high relative densities of up to 89.48 % and 99.57 %, respectively. The shear strain due to significant lattice distortions caused by differences in elemental size, mass and electronegativity increased resistivity through enhancing phonon scattering. Meanwhile, this strain effect and native defects changed the charge conduction mode, thus resulting in a significant linearity at critical temperatures exceeding 163 K. Our results reveal that the high-entropy enhances the performance of LaCrO3 materials for thermistor applications, especially in terms of improving the ceramic density, reducing the resistivity and enhancing the temperature sensing accuracy. This high-entropy approach is expected to be widely applicable for the development of high-performance low-temperature thermistors.

Recovery of Ni-Co-Mn Oxides from End-of-Life Lithium-Ion Batteries for the Application of a Negative Temperature Coefficient Sensor

This study demonstrates the current advancements in battery management systems (BMSs), emphasizing the need for precise temperature monitoring within battery packs to enhance safety and performance through efficient thermal management. The increased demand for lithium-ion batteries (LIBs) has driven the development of temperature sensors with improved accuracy and stability. In particular, Ni-Co-Mn-based spinel oxides are commonly used due to their stable negative temperature coefficient (NTC) behavior. However, challenges arise in manufacturing due to the high cost and uncertain supply of critical cathode components (e.g., Co, Ni, and Mn) for LIBs. This research focuses on developing spinel-type (Ni0.6Co0.4Mn2)O4 using recycled Ni-Co-Mn oxides obtained from end-of-life (EOL) LIBs, demonstrating temperature resistance behavior suitable for temperature sensing. The oxides are prepared through hydrometallurgy, oxalate synthesis, and post-heat treatment. Successful integration into spinel-type NTC thermistors suggests broader applications in various industrial fields. A systematic investigation into the synthesis and characterization of recovered Ni-Co-Mn oxides from EOL LIB cathode materials (Li(Ni0.33Co0.33Mn0.33)O2) is presented for NTC thermistor application. Thermogravimetric analysis-derivative thermogravimetry (TGA-DTG) identifies the optimal post-heat treatment temperature. The X-ray diffraction (XRD) patterns confirm a cubic spinel structure of the Ni-Co-Mn oxides, supported by scanning electron microscope (SEM) images showing a uniform microstructure. Also, energy dispersive X-ray spectroscopy (EDS) mapping confirms homogeneous element distribution. Recovered oxide pellets from the sintering process exhibit a single spinel structure, with X-ray photoelectron spectroscopy (XPS) analysis revealing changes in the valence states for Ni and Mn. Resistivity measurements demonstrate semiconductive behavior, which shows a B value (3376.92 K) suitable for NTC thermistor applications. This study contributes valuable insights to black powder recycling from EOL LIBs and its potential in temperature-sensitive electronic devices.

High-entropy chromate (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)CrO3 for high-temperature NTC thermistors

This paper presents a novel rare earth-based chromate (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)CrO3 for high-temperature thermistor applications. X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy tests reveal that the material is a high-entropy ceramic with a perovskite structure, exhibiting a dense microstructure with a relative density of 97.6 %. Electrical analysis shows that (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)CrO3 exhibits high resistivity at high temperatures but with a material constant of 1,968 K, making it capable of meeting the resistance requirements for commercial thermistors over an ultrawide temperature range of 25 – 1,300 °C. AIMD simulations indicate the excellent structural stability of (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)CrO3 even at 1,300 °C, suggesting promising high-temperature aging characteristics. Further aging tests demonstrate that its resistance only drifted by 4.57 % after being subjected to 1,300 °C for 1,000 h. The above findings represent breakthroughs in terms of maximum operating temperature, applicable temperature range, aging performance and sintering densification for chromate-based high-temperature thermistor ceramics.

Dielectric, electric, and magnetic response of modified bismuth ferrite-based double perovskites for NTC-thermistor application

Owing to the variation of the characteristics due to the cationic substitution of diverse elements at both A and B sites, the new polycrystalline double perovskite BaBiFeMnO6, synthesized via a cost-efficient solid-state reaction route. Initial structural refinement by Rietveld analysis reveals material crystallised in dual phases i.e. monoclinic and orthorhombic. The respective cell parameters for monoclinic as well as orthorhombic phases are a = 5.5881 Å, b = 5.6541 Å, c = 7.9186 Å with cell angles α = γ = 900 and β = 89.90810 and a = 5.4807Å, b = 5.3583Å, c = 7.4045Å and refined angles are α = β = γ = 900 respectively. The microstructural interpretation of the present sample reflects a non-uniform distribution of the grains with an average grain size of 2.97 μm with a mean crystalline size of 342.65 nm. The Fourier-Transform Infrared Spectroscopy (FTIR) graph indicated that the sample belongs to the perovskite family. The impedance measurement was carried out in a selected frequency and an assigned temperature range to investigate the electrical features of the material which suggested the non-Debye type relaxation and negative temperature coefficient of resistance (NTCR). Furthermore, the thermistor constant (β) and temperature coefficient of resistance (TCR) contributed to investigating the NTCR characteristic of the sample under NTC-type thermistor applications. The room temperature dielectric constant is 1707.67 with a minimal tangent loss of 0.7069 at 100Hz frequency has been estimated by fitting the dielectric data by utilizing the Havrilliak-Negami function. The polarization (P) induced due to the maximum applied electric field of 1.287 kV is studied from the hysteresis loop plotted between them. The hysteresis loop indicates the ferroelectric property of the material with a lossy nature. The room temperature remnant magnetization (2Mr) of 0.4424 emu/g and coercivity (2Hc) of 6.2 kOe have been estimated from the M ∼ H loop. The potentiality of the material to be used as a viable candidate in various energy storage devices and supercapacitors is suggested by all of the characterisations in conjunction with the high value of εr i.e. ∼80000 at 300 °C for the lower frequency.

Conductive polymer biocomposites based on poly(3-hydroxybutyrate) and poly(butylene adipate-co-terephthalate) with various graphene fillers for thermistor applications

Conductive polymer biocomposites based on poly(3-hydroxybutyrate) and poly(butylene adipate-co-terephthalate) with various graphene fillers for thermistor applications

The Specifics of PTC Thermistor Applications for Limiting Surge Currents

This paper investigates the possibilities of limiting emergency short current pulses by using materials with a positive temperature coefficient. A computational model and method for simulating this process were proposed. Barium titanate was considered a promising material for current-limiting devices due to its low cost, ease of manufacturing and autonomy. The current-limiting properties of a PTC thermistor device were estimated in relation to a significant pulse current overload (10 ms). The value of taking into account the varistor effect when modeling energy dissipation by a PTC thermistor is experimentally demonstrated. The results of the experiment were used in the development of computer models of the current-limiting properties of PTC thermistors. A method for taking into account the varistor effect in the developed models is proposed. It is noted that in order to increase the accuracy of the calculation, it is important to take into account the heat transfer between the PTC thermistor and its contact system. It is also shown that this heat transfer is capable of creating a significant longitudinal temperature gradient inside the PTC thermistor, which creates a high level of thermal stress and leads to mechanical failure. Destruction of this type has been observed during experiments. This research was carried out within the state assignment FSEG-2023-0012.

High specific capacitance and NTC behavior of substituted cobalt oxide spinels for electrochemical supercapacitor and thermistor applications

Due to the growing importance of low-cost energy storage devices in smart device applications, finding an appropriate electrode material with the least self-discharging, high power, and energy densities is the need of the hour. In this paper, Cu and Mn-modified Co3O4 spinels in the form of CuCo2O4 and MnCo2O4 are reported as the most promising electrode materials for high-performance electrochemical supercapacitors. Modified Co3O4 spinels were prepared by the co-precipitation technique, and the X-ray diffraction (XRD) studies show a single-phase formation with cubic crystal symmetry. The average crystallite size estimated by considering the highest intensity peak of the diffraction pattern using Scherrer’s relation shows the average crystallite size below 30 nm for reported spinels. Scanning electron microscopic (SEM) images stabilize the fact that grains with nanosizes consisting of regular shapes and excellent morphological features. The dc-conductivity measurement establishes the essence of negative temperature coefficient of resistance (NTCR) behavior in nanostructured spinels. The specific capacitance (Cs) of CuCo2O4 and MnCo2O4 estimated using cyclic voltammetry (CV) was found to be 616.074 F g−1 and 1401.16 F g−1 for a scan rate of 10 mV s−1 with verified stability up to 1000 cycles. The low internal resistance value in the range of 0.1 Ω for both the spinels verified by the electrochemical impedance spectroscopy (EIS) graph confirms these spinels as encouraging electrode materials for electrochemical supercapacitors.

Characterization of NTC thick film thermistor paste Cu0.2Ni0.5Zn1.0Mn1.3O4

A powder of Cu0.2Ni0.5Zn1.0 Mn1.3O4 composition for custom thermistor was prepared by using the respective mixture of metal oxides and solid state reaction at 1000 ?C/4h in air. The obtained thermistor powder was milled in the planetary ball mill and agate mill for a prolonged time to achieve submicron powder. The prepared thermistor powder was further characterized by using XRD and SEM techniques. After that, the thermistor powder was pressed into small disc-shaped samples and sintered at 1150?C/2h. The sintered samples were also characterized by using XRD and SEM. The main electrical properties such as nominal resistance R and thermistor exponential factor B were measured in the climatic test chamber. After that, the thick film paste was prepared using the same powder, an organic vehicle and a glass frit. The paste was printed on alumina substrate, dried at 150 =?C /30 min and sintered in air at 850?C /10 min in a hybrid conveyor furnace. Planar electrodes were printed on the sintered NTC thermistor layer using PdAg thick film paste. The electric properties of the sintered thick film thermistor were also measured in the climatic test chamber. The obtained results were used for development of novel self-heating thermistor applications.

Enhancement in the linear electrical properties and thermal stability of chromite perovskites through entropy engineering

Energy band structure of LaCrO3-based ceramics is modified by entropy engineering to enhance the linear electrical properties and thermal stability in low-temperature thermistor applications.

Synthesis of a scheelite barium molybdate: Structural, topological, electrical, and transport properties for negative temperature coefficient thermistor application

Preliminary structural analysis of Scheelite barium molybdate BaMoO4 (BMO) ceramic using NTREOR-09 and McMaille methods has confirmed the tetragonal symmetry with room temperature X-ray diffraction (XRD) spectrum. Further, other structural parameters like crystallite size and compressive lattice strain are found to be of 31 nm and −0.00151 respectively. The topographical study of scanning electron microscope (SEM) image confirms the polycrystalline nature with no other impurities in the sample. Detailed analysis of dielectric permittivity (εr), and loss (tanδ) supports Maxwell-Wagner and Koop's phenomena. The non-overlapping small polaron tunnelling (NSPT) and correlated barrier hopping (CBH) model have emphasis on transport mechanism. The presence of semiconducting behavior of the scheelite material at various temperatures and frequencies examined by complex impedance and modulus spectra. The value of grain resistance decreases as temperature increases demonstrating the existence of negative temperature coefficient (NTCR) behavior of the material. The increase of the value of thermistor constant (β) (67.339, 516.613, and 772.485 in the different high-temperature range) suggests an efficient application of the material for NTC-thermistor.

Widening the temperature range and improving the linearity of CaCu3Ti4O12 ceramics for high-temperature NTC thermistor application through entropy engineering strategy

The entropy engineering strategy has been used for the first time to improve the grain boundary (GB) barrier of CaCu3Ti4O12 (CCTO) ceramics, in order to solve its nonlinear problem at around 300 ℃ and expand its application in the field of high-temperature thermistors. To achieve this goal, we prepared (CaBaEuZnSr)0.2Cu3Ti4O12 (CBEZSCT) high-entropy ceramics, and the GB spontaneous segregation properties were exploited to improve the GB resistance of CBEZSCT ceramics. The results show that the GB activation energy of CBEZSCT high-entropy ceramics (0.87 eV) is higher than that of CCTO ceramics (0.7 eV), which linearizes the resistance temperature curve and extends the application temperature limit from 300° to 750 °C. The proposed method of using a high entropy strategy to tune the GB resistance of CCTO to optimize its performance is highly effective, thus providing a new way of thinking about studying high-performance CCTO materials.

A brownmillerite electronic material LiBiFe2O5: structural, dielectric, electrical, and ferroelectric properties for device application

ABSTRACT A lead-free brownmillerite ferroelectric material LiBiFe2O5 (LBFO) has been synthesized via a solid-state reaction technique. Using the procedure of N-TREOR method of X-ray diffraction, the crystal structure of the prepared sample is found to be monoclinic with lattice parameters: a = 13.6726 Å, b = 4.1560 Å, c = 8.5317 Å, and β = 102.89˚. Based on analysis of electrical data, the existence of Koop's and Maxwell–Wagner relaxation phenomena and dielectric relaxation in the material has been confirmed. This analysis has also shown a high impact of the dielectric permittivity (ϵr) and low tangent loss (tanδ) on using the material in some electronic devices. A detailed study of the frequency-temperature-dependent ac conductivity has suggested the presence of Jonscher's universal power law in the material. As the material has thermistor constant (β) values of 4019.26, 11535.75, and 484.36 in different temperature ranges indicating high-temperature NTC thermistor application.

New high temperature negative temperature coefficient thermistors in Mg0.5Mn0.5AlFeO4 ceramics

For high temperature thermistor applications, the MgAl2O4 exhibits poor conductivity and requires high sintering temperature for ceramic densification. In this study, we have reported on the preparation and characterization of spinel Mg0.5Mn0.5AlFeO4 ceramics by solid solution modification. The resultant ceramics exhibit a combination of high temperature stability and semi-conductivity, which are the characteristics of MgAl2O4 and MnFe2O4. The material has a moderate thermistor constant, which is in favor of application at high temperatures and a wide temperature range. The electrical conductivity is due to the small-polaron hopping in different valence states of manganese and iron ions. Our findings demonstrate a promising approach to extend the applicability of spinel ceramics for high temperature thermistors.

Effect of Incorporating Graphene Oxide in ZnO and Study of the Thermistor Applications of ZnO-RGO Film

This research reported the effect of incorporating graphene oxide in the hybrid of ZnO and investigated the thermistor applications. ZnO-RGO were synthesized by the hydrothermal method and spin coated on glass to obtain the thin film. The SEM micrograph of ZnO-RGO showed mini ZnO nanorods decorated and formed on the RGO sheet. The adherence of the nanorods were improved as the loading mass of GO increased in the composite. ZnO-RGO had thermal sensing response of 3.1 respectively at 573K and showed improved electrical conductivity as temperature increased. ZnO sensors logged a negative temperature coefficient (NTC) value of 0.00236 /K and a sensitivity value of 0.01392 Ω/ K while ZnO-RGO had a NTC value of 0.00248139 /K (which is higher than values obtained in literature for silver and palladium based graphene composites) and a sensitivity value of 0.00769 Ω/ K. A value of 0.0561eV was obtained for the activation energy of ZnO sensor while 0.0615 eV was obtained for ZnO-RGO. This research has confirmed that incorporating GO in ZnO increased the activation energy of ZnO-RGO thermistor, and consequently increased the thermal sensing response thus resulting in improved thermal sensing properties of ZnO. With an improved NTC, sensor response and activation energy, ZnO-RGO can replace Pd based RGO and Ag nanoparticles based RGO as thermistors.

Lead-free complex double perovskite SrLiFeWO6: Structural, microstructure, electrical and optical study

In this work, synthesis (solid-state reaction) and characterizations (structural, microstructure, dielectric, conductivity, Raman & UV–vis) of a newly prepared lead-free complex perovskite SrLiFeWO6 are reported. Preliminary X-ray diffraction (XRD) analysis suggests a tetragonal phase. The scanning electron microscope (SEM) micrograph and energy dispersive x-ray analysis (EDX) spectrum show the well-grown grains and sample purity. The study of Raman active lines determines the vibrational modes of the constituent molecules in the reported compound. Dispersed dielectric plots were explained by the Maxwell-Wagner polarization effect. The modulus study reveals the presence of a non-Debye type of relaxation. Jonscher's Power Law is fitted in ac conductivity data which follows a correlated barrier hopping mechanism. The direct bandgap energy of the studied sample is found to be 1.68 eV, which may be a good range for photovoltaic applications. For NTC thermistor applications, the analyzed thermistor constant and sensitivity factor are found to be within the permissible range. The idea of ferroelectric nature is opened up by the study of polarization versus electric field. The examination of current density versus electric field reveals that the sample has an ohmic character in the low region and a space charge-limited conduction (SCLC) mechanism in the higher field region.

Development of a novel triple perovskite barium bismuth molybdate material for thermistor-based applications

In this communication, development (synthesis and characterization) of a novel triple perovskite sample Ba3Bi2MoO9 (BBMO) is reported. The material has monoclinic crystal symmetry. A detailed study of microstructure and compositional analysis of the sample by using scanning electron microscopy (SEM) and EDX (energy dispersive X-rays) spectrum has provided the quality of the BBMO ceramic. The topological and surface roughness of the novel material has been analyzed to clarify the surface texture and compactness of the sample surface. The variation of conductivity under the alternating current of the material varies according to the Jonscher's universal power law. The high dielectric constant and low tangent loss are applicable for fabrication of various electrical instruments. The resistance decreases with an increase in temperature supports the NTCR (negative temperature coefficient of resistance) behavior, which is clarified by using TCR and β (thermistor constant) for NTC thermistor application.