The role of Ca2+ ions in the formation of high optical quality Cr4+,Ca:YAG ceramics

Effects of divalent dopants on the microstructure and conversion efficiency of Cr4+ ions in Cr,Me:YAG (Me - Ca, Mg, Ca/Mg) transparent ceramics

“…The resulting mixture was dried in a drying cabinet for 24 h and then compacted by isostatic pressing at 250 MPa. The solid-phase synthesis was carried out in a vacuum oven at a temperature of 1750°C for 10 h. This procedure is described in more detail in our previous reports [26][27][28]. The Cr 3+ oxidation to the tetravalent state was achieved by annealing the samples in air at 1450°C for 15 h. The composition and the temperature used during the manufacturing of each sample are presented in Table 1.…”

“…Due to the complicated process of intercalation of Me 2+ ions into YAG, the XRD results are not enough to determine the location of Me 2+ incorporation into YAG structure. For example, recently the microstructure of Cr,Ca:YAG ceramics was investigated by means of high-resolution electron microscopy [27]. Inhomogeneous distribution of Ca 2+ ions in YAG grains was shown, caused by the formation of Ca-rich layer of the same crystal structure and crystallographic orientation as the original grains.…”

Effect of Ca2+ and Mg2+ ions on the sintering and spectroscopic properties of cr‐doped yttrium aluminum garnet ceramics

“…They also suggested an interaction between CaO and Cr 2 O 3, resulting in the appearance of a liquid phase on the grain boundaries, which affects the densification process. In their subsequent studies, 27 the role of Ca 2+ ions in the formation of transparent Cr 4+ , Ca:YAG ceramics was further explored. They revealed an inhomogeneous distribution of Ca 2+ ions which occurs after vacuum sintering.…”

“…In the present study, we investigated the effects of addition of silicon, magnesium, and calcium oxides and the annealing temperature on the spectroscopic properties and microstructure of the Cr:YAG ceramics. The emphasis was put on samples containing only MgO as a charge compensator, since other researchers focused on the spectroscopic properties of Cr 4+ :YAG co‐doped with CaO or different CaO/MgO systems 5,22‐27 . The effect of a solely MgO addition was presented for pure YAG, 15,28 Nd:YAG, 29,30 and Yb:YAG 31 .…”

Effect of Yb concentration on the microstructures, spectra, and laser performance of Yb: CaF2 transparent ceramics

“…Hence, transparent ceramics is a very potential laser gain medium. Most of the transparent ceramic focuses on oxide materials like YAG, 3,4 sesquioxide, 5,6 MgAl 2 O 4 , 7,8 etc. Recently, fluoride‐based transparent ceramics have attracted significant interests due to their high transparency, low phonon energy and refractive index 9‐12 .…”