Negative Temperature Coefficient Thermistors in Ceramic Materials

Negative temperature coefficient (NTC) thermistors are ceramic semiconducting resistors whose electrical resistance decreases with rising temperature. Predominantly based on transition‐metal oxide spinels—such as nickel manganite (NiMn₂O₄), manganese cobalt nickel oxide (Mn–Co–Ni–O) and related substituted compositions—these materials exhibit strong thermally activated conduction governed by charge‐carrier hopping between transition‐metal cations. The magnitude of the temperature‐sensitive resistivity is often expressed by the thermistor constant (B value), which reflects the activation energy of conduction. Ceramic processing routes, including solid‐state sintering, co‐precipitation, aerosol deposition and thin‐film sputtering, yield dense microstructures characterised by controlled grain and grain‐boundary characteristics. Optimisation of stoichiometry, dopant levels and microstructural features—such as twin domains, porosity and phase purity—permits fine tuning of resistivity, B value and long‐term stability. Such NTC ceramics are integral to precision temperature sensing in automotive systems, consumer electronics, energy monitoring and safety applications, owing to their rapid thermal response, high reproducibility and compatibility with multilayer architectures.

Research from Nature Portfolio

Recent studies have demonstrated that deposition of Mn–Co–Ni–O spinel nanofilms via sputtering from acetate precursors can achieve highly oriented, dense films with enhanced temperature coefficients of resistance and moderate resistivity. By matching precursor decomposition temperatures to film crystallisation conditions, these thin films exhibit microsecond‐scale electronic recombination rates, intrinsic n‐type conduction and stable high‐temperature performance. Such advances in thin‐film processing provide a pathway towards miniaturised, high-speed NTC devices for advanced oxide electronics and infrared sensing applications.

Negative Temperature Coefficient Thermistors in Ceramic Materials publication trend

The graph below shows the total number of articles in negative temperature coefficient thermistors in ceramic materials across all publications each year (not limited to Nature Index journals).

Technical terms

Negative Temperature Coefficient (NTC) thermistor: A ceramic resistor whose electrical resistance decreases as temperature increases, used for sensing and regulation.

Spinel structure: A cubic crystal lattice (AB₂O₄) in which divalent and trivalent metal cations occupy specific tetrahedral and octahedral sites, conferring semiconducting properties.

Thermistor constant (B value): A parameter that quantifies the sensitivity of resistance to temperature, related to the activation energy of charge‐carrier conduction.

Polaron hopping: A conduction mechanism in which charge carriers (electrons or holes) move by jumping between adjacent metal cations, assisted by lattice polarisation.

Grain boundary: The interface between crystalline regions in a polycrystalline ceramic, which can dominate resistive behaviour and ageing stability.

Sintering: A thermal process that densifies ceramic powders into solid bodies by mass transport and grain‐boundary diffusion, reducing porosity and enhancing mechanical integrity.

Activation energy: The minimum energy required to enable charge‐carrier movement between sites, determining the temperature dependence of conductivity.

References

1. High performance of Mn-Co-Ni-O spinel nanofilms sputtered from acetate precursors. Scientific Reports (2015).
2. Enhanced conductivity and stability of Co 0.98 Cu x Mn 2.02− x O 4 ceramics with dual phases and twin structures. Journal of Advanced Ceramics (2023).
3. Enhanced aging and thermal shock performance of Mn1.95−xCO0.21Ni0.84SrxO4 NTC ceramics. Journal of Advanced Ceramics (2021).
4. Novel Method for NTC Thermistor Production by Aerosol Co-Deposition and Combined Sintering. Sensors (2019).