Differential spectroscopic properties of Nd3+ in NdGa03 and LaGa03

The NdGaCO3 and LaGa03 crystals are orthorhombic perovskites, belonging to space group D162h Pbnm. The Nd3+ spectroscopic properties including both optical absorption and emission in both compounds were measured at different temperatures between 9 and 300 K. Very high neodymium concentration is the reason for the quenching of the luminescence in the Nd compound but it allows us to observe all possible electronic transitions in the 200–2500 nm region. The spectra are partially polarized. Though the energy level positions in both compounds are essentially the same, there are some unusual aspects of the Nd compound as compared with the behavior of the La one that can not be explained by current single ion theories.