Luminescence thermometry based on negative thermal expansion host matrices.

In practical applications involving high temperatures in oxides and oxide-based structures, challenges such as flames and aggressive environments are common. Turbine engines, where oxide coatings are crucial, face difficulties in temperature measurement due to rapid part motion. The emergence of luminescence thermometry offers advantages in such scenarios and has been studied extensively. However, thermal quenching (TQ) of luminescence happening at such conditions limits the use of phosphor materials as luminescence thermometers for high-temperature sensing, thereby restricting the achievement of sufficient sensitivities and temperature resolutions. Thus, thermally stable phosphors, or more favorably phosphors with anti-TQ of luminescence, have been explored to address TQ issues of luminescence thermometry in recent years. Particularly, phosphors based on negative thermal expansion (NTE) as host matrices have shown feasibility in luminescence thermometry at temperatures exceeding 600 °C. This review focuses on NTE-based phosphors, addressing their luminescent properties and analytical techniques for extending the temperature measurement range. The aim of this review is for better understanding of the structural changes with temperature of NTE-based phosphors, assessing their potential for temperature sensing in harsh conditions, and ultimately encouraging researchers to explore new NTE-based phosphors. The article comprehensively reviews luminescence thermometry using negative thermal expansion (NTE) host matrices. It highlights the challenges of thermal quenching in traditional luminescence thermometry at high temperatures and discusses the advantages of using NTE materials to address these challenges. The review covers principles, applications, and advancements in the field, emphasizing NTE-based phosphors for high-temperature sensing and their potential for improving temperature measurement accuracy in harsh conditions. It discusses individual NTE materials and composite phosphors composed of NTE and positive thermal expansion hosts, showcasing their performance in temperature sensing through detailed examples and research findings. [Display omitted] • Summarizes significant advancements in thermometric temperature measurement techniques. • Showcases NTE host materials for luminescence thermometry. • Reviews the impact of NTE properties on the thermal quenching process. • Contributes to the fundamental understanding of NTE materials in optical thermometry. • Opens new pathways for developing efficient temperature sensors for industrial applications. [ABSTRACT FROM AUTHOR]