Evidence for a double doping regime in Nd:YAG nanopowders
Nanopowders of Yttrium Aluminium Garnet doped with neodymium (Nd:YAG) were investigated by X-Ray Absorption Fine Structure (XAFS) at the Nd LIII edge in the 1.3–20.8% doping range. XANES spectra appear similar in the full range of the Nd concentration. However, a significant decrease in the white line intensity of XANES is revealed as the quantity of Nd doping ions increases. Plotting the white line intensity as a function of Nd doping ions reveals two linear trends with two different slopes, identifying a threshold value where the neodymium concentration reaches 5 at.% This experimental finding provides support for the existence of a double doping regime in Nd:YAG nanopowders.
KeywordsXANES Spectrum Garnet Phase White Line Intensity Neodymium Concentration Neodymium Doping
The authors would like to thank MIUR for supporting this research through the PRIN 2007 prot. 20077R3PXF_002 “New nanocomposite preparation for optical, electric and magnetic applications.” TEM experimental data were provided by Centro Grandi Apparecchiature—UniNetLab—Università di Palermo funded by P.O.R. Sicilia 2000–2006, Misura 3.15 Azione C Quota Regionale. XAS measurements at Daresbury Laboratory were funded by the European Community—Research Infrastructure Action under the FP6 “Structuring the European Research Area” Programme (through the Integrated Infrastructure Initiative “Integrating Activity on Synchrotron and Free Electron Laser Science”). Thanks are due to S. Fiddy (Daresbury Laboratory) for his help in the execution of the measurements.