In this work we tried to establish a convenient ceramics preparation method to obtain LiGaSiO4 phase as the predominant one in LiGaSiO4-LiGa5O8-Li5GaSi2O8 system containing few Cr3+ ions as substitutional impurity. The powder samples were produced by solid state reaction from high purity Li2CO3, Ga2O3, SiO2 and Cr2O3 powders. At first, the oxides were mixed during 2 h in an agate mortar and pressed into discs with dimensions 10 mm in diameter and 2 mm in thickness. The discs were fired in air for 72 h at 1000ºC under atmospheric pressure. This first sample of discs was cooled down inside the furnace. With the objective of varying the ratio between the phases, a new sample was prepared by 6 h milling followed by pressing into discs with 2 t charge and 90 h firing at 1000ºC. The two samples obtained were investigated by X-ray diffraction, for determining the phases formed. Finally, photothermal spectroscopy measurements were carried out. The broad absorption and emission bands in the visible and near-infrared spectral regions presented by these materials constitute the motivation for their study. These bands are tunable and allow a large number of applications: in medicine, communications and solid state lasers, for example.
Ceramics; Cr3+; photothermal spectroscopy
