Optical absorption of MnGa2S4 single crystals

Based on the absorption spectra studies in a wide temperature and wave-lengths region, the peculiarities of the MnGa9S4 absorption spectra at 2.49 and 2.65 eV are shown to be attributed to the absorption on intracentered transitions of two-valent ions, Mn2+[6A1→4T2(4G)] and 6A1(6S)→A1, 4E(4G). The fundamental absorption edge is formed by the direct allowed transitions. The temperature coefficient of the band gap has been determined.