Sm<sub>1–<i>x</i></sub>La<sub><i>x</i></sub>Fe<sub>3</sub>(BO<sub>3</sub>)<sub>4</sub> (<i>x</i> = 0, 0.75) single crystals
were synthesized using the flux method.
The crystal nucleation procedure and flux parameters are reported.
Conditions for growing the Sm<sub>1–<i>x</i></sub>La<sub><i>x</i></sub>Fe<sub>3</sub>(BO<sub>3</sub>)<sub>4</sub> (<i>x</i> = 0, 0.75) single crystals are described.
The prepared crystals were studied by Raman spectroscopy in the temperature
range of <i>T</i> = 10–300 K. The spectral region
corresponding to temperatures of <i>T</i> = 10–55
K, which involves the temperatures of the magnetic phase transition <i>T</i><sub>N</sub> = 32 K for <i>x</i> = 0 and <i>T</i><sub>N</sub> = 31 K for <i>x</i> = 0.75, was
thoroughly analyzed. Anomalies related to the magnetic ordering established
in both compounds were found. The main changes occur in the low-wavenumber
region (up to 100 cm<sup>–1</sup>), where the mode corresponding
to magnon scattering arises. This mode is shown to have the internal
structure indicative of the occurrence of unstable vibrations (40–80
cm<sup>–1</sup>). The results obtained are analyzed by calculating
the empirical lattice dynamics in Sm<sub>1–<i>x</i></sub>La<sub><i>x</i></sub>Fe<sub>3</sub>(BO<sub>3</sub>)<sub>4</sub> with <i>x</i> = 0 and <i>x</i> =
1
