Remarkably stable luminescence thermometric performance of upconverting LiYF4:Yb3+, Tm3+ nanoparticles obtained via an anhydrous precursor strategy

Significantly enhanced thermometric performance and constant sensitivity (Sr) over a wide range of temperature (300–500 K) are reported for the NaYF 4 :Yb 3+ , Tm 3+ nanoparticles obtained through thermal decomposition of home-made anhydrous precursors. Given their excellent optical properties, the lanthanide-containing nanomaterials are fast emerging as promising candidates for highly sensitive thermometry. This work describes the thermometric performance of high quality tetragonal LiYF 4 : Yb 3+ , Tm 3+ NPs synthesized using home-made anhydrous precursors [Ln(TFA) 3 (monoglyme)] and [Li(TFA)(monoglyme)] (Ln = Y, Gd, Tm, Yb; TFA = trifluoroacetate) in a hot-injection method. These NPs show excellent constant relative sensitivity (>1%.K −1 ) and stability over a wide range of temperature (300–500 K), indicating that they are good candidate for temperature-sensing applications requiring a wide range of temperature. In addition, reactions between Gd(TFA) 3 (H 2 O) 3 and Li(TFA)(H 2 O) in the presence of N -methyl substituted amino alcohols were also investigated in relation with their use as precursors for LiGdF 4 matrix-based upconverting nanoparticles. One of these reactions resulted in the isolation of a homometallic cluster [Gd 4 (OH) 4 (TFA) 8 (mdeaH 2 ) 3 (THF)]. 2 THF ( 1 , mdeaH 2 = N -methyl diethanolamine), which was structurally characterized. The difficulty in getting LiGdF 4 NPs from the thermal/microwave co-decomposition of lithium and gadolinium trifluoroacetates are discussed.