Influence of Magnetic Gd3+ Ion on the Intensity of Mn4+ R-Line in Oxides with Perovskite Structures

The purpose of this paper is to show that the Mn4+ 2E4A2 spin forbidden emission transition (R-line) is intensified in Gd3+ based compounds with the perovskite ABO3 and double perovskite A2BB'O6 structures. The intensity of the R-line is compared in compounds with non-magnetic ions such as Y, La and Eu. and those with Gd ion. The significant increase in the intensity of the spin forbidden transition is explained by a simple model of exchange coupling in the dimeric unit, Mn4+-O2- -Gd3+. It is also pointed out that exchange interaction between the Mn4+ and Gd3+ ions cause significant broadening of the R-line in compound having the pyrochlore structure.