Synthesis and characterization of room-temperature ferromagnetism in Fe- and Ni-co-doped In2O3

Observation of room-temperature ferromagnetisin in Fe- and Ni-co-doped In2O3 samples (In0.9Fe0.1-xNix)(2)O-3 (0 <= x <= 0.1) prepared by citric acid sol-gel auto-igniting method is reported. All of the samples with intermediate x values are ferromagnetic at roomtemperature. The highest saturation magnetization (0.453 mu B/Fe + Ni ions) moment is reached in the sample with x = 0.04. The highest solubility of Fe and Ni ions in the In2O3 lattice is around 10 and 4 at%, respectively. The 10 at% Fe-doped sample is found to be weakly ferromagnetic, while the 10at% Ni-doped sample is paramagnetic. Extensive structure including Extended X-ray absorption fine structure (EXAFS), magnetic and magneto-transport including Hall effects studies on the samples indicate the observed ferromagnetism is intrinsic rather than from the secondary impurity phases. (c) 2007 Elsevier Ltd. All rights reserved.

Synthesis and characterizations of Al-doped Zn0.95Ni0.05O nanocrystals

Nanocrystalline Zn0.95-xNi0.05AlxO (x = 0.01, 0.02, 0.05 and 0.10) diluted magnetic semiconductors have been synthesized by an autocombustion method. X-ray absorption spectroscopy, high-resolution transmission electron microscopy, energy-dispersive spectrometry and Ni 2p core-level photoemission spectroscopy analyses revealed that some of the nickel ions were substituted for Zn2+ into the ZnO matrix while others gave birth to NiO nanoclusters embedded in the ZnO particles. The Zn0.95Ni0.05O sample showed no enhancement of room-temperature ferromagnetism after Al doping. (C) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Synthesis and luminescence characterization of cerium doped Lu2O3-Y2O3-La2O3 solid solution transparent ceramics

Ce3+:( Lu0.7Y0.25La0.05)(2)O-3 transparent ceramics were fabricated with nanopowders and sintered in H-2 atmosphere. The spectral properties of Ce3+:( Lu0.7Y0.25La0.05)(2)O-3 transparent ceramics were investigated and the luminescence of Ce3+ in the solid solution of Lu2O3, Y2O3 and La2O3 has been found. The ceramics has high density of 8.10g/cm(3) and short fluorescence lifetimes of 7.15 ns and 26.92 ns. It is expected to be a good fast response high temperature inorganic scintillating materials. (C) 2008 Optical Society of America.

Spectral investigation of Yb-doped calcium pyroniobate crystal

Ytterbium-doped calcium pyroniobate single crystal has been grown for the first time. Spectral properties of Yb: Ca2Nb2O7 were investigated by emission and absorption spectra. Its cooperative luminescence and fluorescence lifetime were also studied. Yb ions in Ca2Nb2O7 showed very broad absorption and emission bandwidth and relatively large absorption and emission cross-sections. Along with other optical properties, this Yb-doped crystal would be a potential self-frequency doubling femtosecond laser gain material. (C) 2007 Published by Elsevier B.V.

Luminescence behavior of Yb(3+)heavy-doped yttrium lanthanum oxide transparent ceramics

Yb3+ heavy-doped yttrium lanthanum oxide transparent ceramics were fabricated and their spectroscopic properties were investigated. The absorption bands of (YbxY0.9-xLa0.1)(2)O-3 (x = 0.05-0.15) ceramics are broad at wavelength of 900-1000 nm. The absorption cross-sections centered at 974 nm and the emission cross-sections at 1031 nm of Yb3+ ion are 0.89-1.12 x 10(-20) cm(2) and 1.05 x 10(-20) cm(2) respectively. The up-conversion luminescence intensity of Yb3+-doped yttrium lanthanum oxide ceramics increased firstly, then decreased with the increase of Yb3+ ion content. (C) 2008 Elsevier B.V. All rights reserved.