Figure 4.

Effect of magnetic fields on the luminescence of 1 and its performance as a luminescent thermometer. (a) Variation of the emission profile of the ⁴F_9/2 → ⁶H_13/2 Dy^III transition under different applied fields. (b) Calculated Zeeman splitting of the lowest m_j levels of ⁴F_9/2, ⁶H_13/2, and ⁶H_15/2 Dy^III electronic levels. (c) Zeeman splitting of the lowest ⁶H_13/2m_j level as obtained from spectroscopy (points) and as estimated from eq 4 (solid lines). The dashed line shows the expected trend considering the Zeeman splitting of the emitting level (⁴F_9/2). Points in part c are color-coded according to the spectra in part a. Luminescence thermometry under applied magnetic fields of (d–f) 0.8 T and (g–i) 7.0 T. (d, g) Emission spectra with the shaded areas indicating the range used for the integration procedure to obtain I₁ and I₂; (e, h) LIR and corresponding S_r values (light and dark cyan points, respectively). (f, i) Uncertainties. Dashed lines in parts f and i mark the δT = 1.0 K threshold.