| Nanoparticles of neodymium doped barium fluoride (Nd:BaF{dollar}sb2){dollar} were synthesized for use as the inorganic component of an optical amplifier composite. Microemulsions were used to maintain domain size in the nano-regime ({dollar}sim{dollar}100 nm), and decreasing the volume fraction of the aqueous content, while simultaneously increasing the volume fraction of the cosurfactant (methanol), gave a linear relationship between decreasing domain size and increasing volume fraction of alcohol. As Nd was added to the BaF{dollar}sb2{dollar} host, direct incorporation was observed at low dopant levels (0-10 mol-%), a two-phase mixture was observed at intermediate dopant levels (10-50 mol-%), and a nearly amorphous product resulted with very high Nd-dopant levels ({dollar}>{dollar}50 mol-%). Fluorescence measurements of the solids showed that concentration quenching was delayed until unusually high levels, probably as a result of the lost crystallinity.; Praseodymium and ytterbium codoped barium fluoride (Pr,Yb:BaF{dollar}sb2){dollar} were also synthesized in microemulsions. Though as-prepared powders did not fluoresce, treatment with high temperatures (900{dollar}spcirc{dollar}C) and dynamic vacuum resulted in products which would fluoresce at 1.3 {dollar}mu{dollar}m. Lower temperature treatments (500-750{dollar}spcirc{dollar}C) were used to decrease sintering, however this resulted in Yb{dollar}sp{lcub}3+{rcub}{dollar} products in which Yb{dollar}sp{lcub}3+{rcub}{dollar} fluorescence was quenched by exposure to air. Contamination due to water and hydroxide is believed to be the reason.; Ethanolic microemulsions were used to make copper phthalocyanine (CuPc), which was modified with either zinc phthalocyanine (ZnPc) or copper phthalcyaninesulfonic acid by means of a flow system. The sulfonic acid derivative was lost upon aqueous washing. The zinc derivatized product gave a dispersion in n-hexylamine, which was stable for seven days. The mole ratio of Cu:Zn was 1:1 for the solids dispersed in n-hexylamine, and was 6:1 for the solids that were not dispersed. Because underivatized CuPc formed by the same method did not result in a dispersed product, the dispersion mechanism is postulated to be due to interaction between the ZnPc on the surface and the n-hexylamine. |
