High-pressure spectroscopic studies of europium gallium and gadolinium aluminum garnets

In this paper we report high-pressure Raman and mid-infrared studies of europium gallium garnet (Eu3Ga5O12) and gadolinium aluminum garnet (Gd3Al5O12). The europium/gadolinium garnets were studied up to 22/10 GPa using Raman spectroscopy and up to 15/22 GPa using infrared spectroscopy. The spectra do not show any clear phase transition over the investigated pressures for both the samples. However, for the case of Eu3Ga5O12 the Raman modes broaden significantly beginning at about 12.5 GPa up to the highest pressure and remain broad even after quenching to atmospheric pressure.