Reply to Comment on “A Mechanistic Understanding of Nonclassical Crystal Growth in Hydrothermally Synthesized Sodium Yttrium Fluoride Nanowires”

Abstract

Figure 1. Value of x in the formula Na 0.5−x Y 0.5+x F 2+2x as a function of reaction time. The line of best fit corresponds to the equation x = −2.32 × 10 −4 t + 7.64 × 10 −2 . Comments pubs.acs.org/cm

Thermochemical Investigation of the Stability and Conversion of Nanocrystalline and High-Temperature Phases in Sodium Neodymium Fluorides

“…17,18 In addition, a β → α transition happens in NaREF 4 when the temperature increases, 19,20 and the thermodynamics of the phase conversion in aqueous solutions needs further research. 21,22 NaNdF 4 nanocrystals can be used as photothermal agents by virtue of the near-infrared absorbing window 23,24 but are more difficult to prepare compared to NaREF 4 nanocrystals with heavier RE elements. 25 In our previous work, the thermochemistry of stoichiometric NaREF 4 with varying RE elements was systematically investigated, showing that the thermodynamic stability of NaREF 4 compounds increases from light to heavy RE elements.…”

“…Many studies involved the α → β phase conversion for NaYF 4 nanocrystals and proposed related crystal growth mechanisms based on the oriented growth of nanoparticles. ,, However, these theories cannot give a good reason for the appearance of the α phase in the low-temperature range (<200 °C), which occurs as high-temperature solid solutions with less NaF than REF 3 in the phase diagrams. , In addition, a β → α transition happens in NaREF 4 when the temperature increases, , indicating the metastability of the α phase of NaREF 4 at room temperature. Hence, the energetic relationship between α and β phases in nanocrystals remains unknown, and the thermodynamics of the phase conversion in aqueous solutions needs further research. , …”