Version 1
: Received: 16 February 2024 / Approved: 19 February 2024 / Online: 19 February 2024 (11:35:39 CET)
Version 2
: Received: 2 March 2024 / Approved: 4 March 2024 / Online: 4 March 2024 (10:37:25 CET)
Version 3
: Received: 16 March 2024 / Approved: 18 March 2024 / Online: 18 March 2024 (10:37:25 CET)
Schiavo, L.; Aversa, L.; Verucchi, R.; Castaldo, R.; Gentile, G.; Carotenuto, G. Negative Temperature Coefficient Properties of Natural Clinoptilolite. Ceramics2024, 7, 452-465.
Schiavo, L.; Aversa, L.; Verucchi, R.; Castaldo, R.; Gentile, G.; Carotenuto, G. Negative Temperature Coefficient Properties of Natural Clinoptilolite. Ceramics 2024, 7, 452-465.
Schiavo, L.; Aversa, L.; Verucchi, R.; Castaldo, R.; Gentile, G.; Carotenuto, G. Negative Temperature Coefficient Properties of Natural Clinoptilolite. Ceramics2024, 7, 452-465.
Schiavo, L.; Aversa, L.; Verucchi, R.; Castaldo, R.; Gentile, G.; Carotenuto, G. Negative Temperature Coefficient Properties of Natural Clinoptilolite. Ceramics 2024, 7, 452-465.
Abstract
Electronic negative temperature coefficient (NTC) materials are usually based on ceramic semiconductors. A new type of NTC-material is represented by zeolites. Indeed, zeolites are single-charge carrier ionic conductors with a temperature-dependent electrical conductivity. In particular, electrical transport in zeolite is due to the monovalent charge-balancing cations, like K+, capable of hopping between negatively charged sites in the silico-aluminate framework. Owing to the highly non-linear electrical behavior of the traditional electronic NTC-materials, the possibility to have alternative types of materials, showing linearity in the electrical behavior, is very desirable. Among different zeolites, the natural clinoptilolite has been selected for investigating the NTC behavior since it is characterized by high zeolite content, convenient Si/Al atomic ratio, good mechanical strength, due to its compact microstructure, and low toxicity. Clinoptilolite has shown a rapid and fully reversible impedance change with heating, characterized by a linear dependence on temperature. The X-ray photoelectron spectroscopy (XPS) analysis has been used for the chemical characterization of the natural clinoptilolite sample as it provides important information on the cationic content and framework composition. In addition, since electrical transport takes place in the free-volume of zeolite, the Brunauer–Emmett–Teller (BET) analysis has been also provided.
Chemistry and Materials Science, Materials Science and Technology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.