Laser-excited site selective spectroscopy of the Eu<sup>3+</sup> ions has been used in malonate crystals to detect a structural phase transition. From room temperature (RT) to 236 K a unique crystal-field site around the Eu<sup>3+</sup> ions is observed. However, two different sites are clearly identified below this temperature indicating a structural phase transition.
The stimulated emission properties of Nd<sup>3+</sup> ions in oxyfluoride glass and glass ceramic have been studied. Ultraviolet and visible emissions generated by upconversion processes inside the laser cavity were also observed. The expected losses produced by these processes have been estimated.