Luminescence of europium ions in lanthanum-magnesium hexaaluminate

The photoluminescence of Eu³⁺ ions in hexagonal lanthanum-magnesium aluminate is studied for the first time. The concentration and temperature dependences of the luminescence intensity and the structure of the spectra of La_1–xEu_xMg·Al₁₁O₁₉ for X = 0.01–1.0 were studied, the existence of several types of luminescence centers (LC) was established. Under excitation, predominantly high-symmetry LC (D_3h) are manifested in the charge-transfer band in the luminescence spectra. A group-theoretical analysis of the structure of the luminescence spectra of europium for possible LC in hexaaluminate with the structural type of magnetoplumbite (space group P6₃/mmc) is carried out.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 45–49, October, 1985.We thank our co-workers at the Laboratory of Vibrations, Institute of General Physics of the USSR Academy of Sciences, for assistance in the experiments on selective laser spectroscopy.