Phonon Spectra and Phase Transitions in van der Waals Ferroics MM${}^{\prime }$P${}_2$X${}_6$

A. Kohutych, V. Liubachko, V. Hryts +6

For CuInP${}_2$S${}_6$ layered ferrielectric crystal, that is most investigated among wide family of van der Waals ferroics MM${}^{\prime }$P${}_2$X${}_6$ (M - Cu, Ag; M${}^{\prime }$ - In, Bi, Cr, $\dots$; X -…