Novel transparent MgGa2O4 and Ni2+-doped MgGa2O4 ceramics

In this study we fabricated, for the first time, magnesium gallate (MgGa2O4, a partially inverted spinel) transparent ceramics, both undoped and doped with 1 at% Ni. The specimens were derived from in-house prepared powder, with a crystallite size of similar to 10 nm (by wet chemistry) and densified by pulsed electric current sintering (PECS; peak temperature 950 degrees C for 90 min). Densification levels of 99.84% and 99.52% of theoretical density were attained for doped and undoped materials, respectively. Doping with Ni was seen to marginally improve the densification level. Quite transparent specimens were produced: the best showing transmission of similar to 89% of the theoretical level (thickness t = 0.85 mm). The absorption spectra revealed that the dopant was accumulated as Ni2+ in the octahedral sites of the lattice, as occurs in single-crystal specimens. After excitation at 980 nm, the doped disks exhibited a wide fluorescence band centered at 1264 nm.

Automated summary

In this study, transparent ceramics of magnesium gallate (MgGa2O4), both undoped and doped with 1 at% Ni, were fabricated for the first time. The specimens were produced from in-house prepared powder and densified by pulsed electric current sintering. Doping with Ni was found to marginally improve the densification level and transparent specimens with high transmission were obtained. The absorption spectra revealed the presence of Ni2+ as the dopant in the octahedral sites of the lattice.