Hydrothermal synthesis and fluorescence properties of γ-NH4Ho3F10 nanocrystals

In this work, pure cubic-phase γ-NH 4 Ho 3 F 10 nanocrystals were successfully synthesized via a facile one-step hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to conduct detailed characterizations of the crystal structure, morphology and size of the as-prepared samples. The fluorescence emission properties of γ-NH 4 Ho 3 F 10 nanocrystals under atmospheric pressure were tested by a fluorescence spectrometer. The as-prepared samples appear white under natural light and exhibit a pink-purple color upon excitation with a 365 nm ultraviolet light. The luminescence lifetime and quantum efficiency of the sample were measured. Under 370 nm excitation, the average lifetime of the sample was approximately 6.6 μs, with a quantum efficiency of 10.17%. Furthermore, high-pressure fluorescence experiments were carried out on the samples with the excitation source fixed at 638 nm. It was found that no changes occurred in the high-pressure fluorescence transitions, from which it is inferred that the γ-NH 4 Ho 3 F 10 nanocrystals maintain structural stability under 12.9 GPa. Therefore, it exhibits promising application potential in fields such as high-pressure sensing and is expected to achieve pressure detection under extreme conditions.