Comparative study of Raman excitations in YVOand HoVO

First-order Raman scattering and multiphonons are studied in RVO3(R$=$Ho and Y) as a function of temperature in the orthorhombic and monoclinic phases. Below T$_{\mathrm{OO}}=$ 200 K in YVO3 and T$_{\mathrm{OO}}=$ 188 K in HoVO3, a G-type orbital ordering (G-OO) with a concomitant monoclinic transition occurs. The orbital ordering enhances the phonon polarizabilities, it also allows the resolution of room-temperature phonons, and activates new excitations around 700 cm$^{-1}$. Below T$_{\mathrm{N}}=$ 114 K (in both compounds), a C-type magnetic ordering (C-SO) occurs and some phonon frequency softening or frequency hardening are observed. Following the structural (monoclinic to orthorhombic) and spin/orbital rearrangement (C-SO to G-SO and G-OO to C-OO) occuring at T$_{\mathrm{N2}}=$ 77 K in YVO3 and T$_{\mathrm{N2}}=$ 40 K in HoVO3, important changes are observed in Raman excitations of both compounds. Even if R ionic radii of HoVO3 and YVO3 are nearly equal (R$_{\mathrm{Ho}}=$ 192 pm and R$_{\mathrm{Y}}=$ 190 pm), we observe some differences that we report.