Lengthening of the Sm&lt;sup&gt;2+&lt;/sup&gt; 4f&lt;sup&gt;5&lt;/sup&gt;5d → 4f&lt;sup&gt;6&lt;/sup&gt; decay time through interplay with the 4f&lt;sup&gt;6&lt;/sup&gt;[&lt;sup&gt;5&lt;/sup&gt;D&lt;sub&gt;0&lt;/sub&gt;] level and its analogy to Eu&lt;sup&gt;2+&lt;/sup&gt; and Pr&lt;sup&gt;3+&lt;/sup&gt;

van Aarle, C.; Krämer, Karl W.; Dorenbos, P.

doi:10.1016/j.jlumin.2023.120329

Lengthening of the Sm²⁺ 4f⁵5d → 4f⁶ decay time through interplay with the 4f⁶[⁵D₀] level and its analogy to Eu²⁺ and Pr³⁺

Title

Lengthening of the Sm²⁺ 4f⁵5d → 4f⁶ decay time through interplay with the 4f⁶[⁵D₀] level and its analogy to Eu²⁺ and Pr³⁺

Author

van Aarle, C. (TU Delft RST/Luminescence Materials)
Krämer, Karl W. (University of Bern)
Dorenbos, P. (TU Delft RST/Luminescence Materials)

Date

2024

Abstract

Recent research activity on Sm²⁺-doped compounds has significantly increased the amount of available data on 4f⁵5d → 4f⁶ decay times. This enabled the systematic comparison of spectroscopic and time resolved luminescence data to theoretical models describing the interplay between the 4f⁵5d and 4f⁶[⁵D₀] excited states on the observed decay time. A Boltzmann distribution between the population of the excited states is assumed, introducing a dependence of the observed 4f⁵5d → 4f⁶ decay time on the energy gap between the 4f⁵5d and 4f⁶[⁵D₀] levels and temperature. The model is used to interpret the origin of the large variation in reported 4f⁵5d → 4f⁶ decay times through literature, and links their temperature dependence to applications such as luminescence thermometry and near-infrared scintillation. The model is further applied to the analogous situation of close lying 4f^n-15d and 4fⁿ states in Eu²⁺ (⁶P_7/2) and Pr³⁺ (¹S₀).