Employing Eu,Tb-doped HfO2 nanocrystals as built-in cryogenic luminescent nanothermometer for commercial coated conductors

This Zenodo repository provides several datasets for a novel approach for detecting quench or hot spot regimes in coated conductors by integrating luminescent nanocrystals onto the silver protective layer, thereby creating a built-in nanothermometer. For this, we employ hafnium oxide (HfO₂) nanocrystals doped with Eu³⁺ and Tb³⁺ ions, synthesized via a microwave-assisted solvothermal method. The optimal nanothermometry system was identified as HfO2:4.5%Eu3+,0.5%Tb3+, which exhibited a relative sensitivity up to 4.80 % K-1 at 40 K. To obtain the built-in nanothermometer, HfO2:Eu3+,Tb3+ nanocrystals were spin-coated onto the coated conductor tapes, forming a nanocrystal-derived thin film with a thickness of 60±10 nm and relative sensitivity of 9.65 % K-1 at 20 K, while still retaining the superconducting properties of the coated conductor.