Magnetic and fluorescence properties of cerium-doped yttrium gadolinium aluminum iron garnet crystals

摘要

Magnetic and fluorescence properties of chemically synthesized Ce:Gd-YAlG (Ce_(0.05)Gd_xY_(2.95-x)Al_(5-y)Fe_yO_(12)) nanocrystals have been investigated. The structural characterization by X-ray diffraction (XRD) shows that a garnet phase has been identified in samples with 0 ≤ x ≤ 2.95 and 0 ≤ y ≤ 3.0. When y = 0_1 only garnet peaks are observed for 0 ≤ x ≤ 2.5, while both garnet and perovskite phases are present for x ＞ 2.5. It is found from XRD Rietveld analyses that the site occupancy of Fe~(3+) at the tetrahedral and octahedral sites in the garnet is independent of the amount of Y~(3+) substituted by Ce~(3+) and Gd~(3+) at the dodecahedral sites. The saturation magnetization for the sample with x = 0 and y= 3.0 is 4.35 emu/g, while that with x = 2.5 and y = 3.0 is 87.5emu/g. When the Fe~(3+) composition y is varied from 0 to 3.0 at x = 2.5, the intensity of fluorescence at the emission wavelength ～570 nm significantly decreases presumably due to absorption by Fe~(3+) that is increased in the crystal.