Thermal conductivity of single crystals of Ca1 − x Er x F2 + x and Ca1 − x Tm x F2 + x solid solutions

Modelling and analyzing the glass-like heat transfer behavior of rare-earth doped alkaline earth fluoride crystals

“…However, unlike the traditional amorphous solids, the increase rate of thermal conductivity would gradually decline in the high-temperature range (over 300 K). 29–32 The same “three-stage” heat transfer characteristic can also be observed in both Er 3+ and Yb 3+ -doped calcium fluoride crystals (Fig. 1b and c), confirming the universality of such a “segmented” heat transfer feature in the doping system.…”

“…[25][26][27][28] The glass-like heat transfer phenomenon from RE doped fluorite crystals has been observed in more than one fluoride system, implying the universality of such heat transfer behavior. 17,18,29 However, the current research on this abnormal thermal behavior is still in its infancy and lacking of well-established theories to explain the relationship between heat transfer behavior and microstructures.…”

“…The fitting parameters in the equation of Ho:CaF 2 , Er:CaF 2 and Yb:CaF 2 with the doping concentration higher than 1 at% (ref [29][30][31]. …”

Numerical model of temperature-dependent thermal conductivity in M1-xRxF2+x heterovalent solid solution nanocomposites where M stands for alkaline-earth metals and R for rare-earth metals

“…There is now a significant amount of experimental thermal conductivity data for M 1−x R x F 2+x fluoride solid solutions where M stands for Ca, Sr, or Ba and R for rare-earth elements (see, e.g., [8][9][10][11][12]). When M = Ca, the transition from single crystals to anti-glass nanocomposites is particularly clear-cut because of the greatest difference in weight between calcium ions and substituent ions R 3+ .…”