Site-Selective Doping and Site-Sensitive Photoluminescence of Eu³⁺ and Tb³⁺ in Perovskite-Type LaLuO₃

Abstract

Eu 3+ and Tb 3+ ions were site-selectively doped into LaLuO 3 with the orthorhombic perovskite-type structure (ABO 3 ), and their luminescence properties were examined considering the doping sites (A or B sites). The X-ray diffraction analysis revealed the expansion or contraction of the unit cell volumes of the materials depending on the doping sites. The spectra of X-ray absorption near edge structure for the Eu and Tb L III edge exhibited different shapes for the ions at A and B sites, confirming the site-selective doping of Eu 3+ and Tb 3+ in LaLuO 3 . The photoluminescence (PL) and PL excitation (PLE) spectra of the materials also showed some differences caused by the doping sites. The intensities of the Eu 3+ PL peaks derived from the 5 D 0 − 7 F 1 transitions and those from the 5 D 0 − 7 F 2 transitions were markedly different between Eu 3+ at A sites and those at B sites because of the different site symmetries. The splitting of the intense Tb 3+ PL peaks originating from the 5 D 4 − 7 F 5 transitions and the absence of PL peaks from 5 D 3 − 7 F J transitions were found only for Tb 3+ at B sites because of the strong crystal field at B sites. In addition to the PL spectra, the positions of PLE peaks originating from charge transfer transitions in Eu 3+ and the 4f−5d transitions in Tb 3+ depended on the doping sites. The successful site-selective doping enabled us to clarify the site-sensitive luminescence properties of Eu 3+ and Tb 3+ doped in the perovskite-type LaLuO 3 .

Site Dependence of Tb3+ Luminescence in Double Perovskite-Type Alkaline Earth Lanthanum Tantalates

“…excitation peaks in the range from 220 to 250 nm. [5][6][7][25][26][27][28][29] The crystal site of Tb 3+ in this assignment is consistent with the results obtained by XRD and XANES measurements. In the PL spectra measured under UV excitation at 247 nm, the Tb 3+ luminescence is composed with two series of transitions from 5 D 3 to 7 F J (J = 6, 5, 4, 3) and from 5 D 4 to 7 F J states.…”

“…19,20 The peak shapes provide the information not only on the valence states of Tb ions but also on the occupied crystal sites. 7,21,22 TbAlO 3 shows a main single peak at 7516 eV and two additional broad peaks at 7528 and 7548 eV, while Ba 2 TbTaO 6 exhibits a main peak at 7517 eV with a shoulder at 7514 eV and two broad peaks at 7533 and 7555 eV. The appearance of the shoulder indicates the splitting of the main peak derived from Tb 5d orbitals in Ba 2 TbTaO 6 .…”

Controllable crystal form transformation and luminescence properties of up-conversion luminescent material K3Sc0.5Lu0.5F6: Er3+, Yb3+ with cryolite structure

“…4(d), all peaks were indexed by cubic crystal with parameters close to those of previously reported K 3 YF 6 compound, and the structural parameters of 2 and 3. 43,44 Based on the site occupation fraction in Rietveld renement, the Er 3+ ions sites, the Er2 3+ ions take up $3.6% Sc2/Lu2 sites and Yb2 3+ ions take up $20.3% Sc2/Lu2 sites. 45,46 Fig.…”

Photosynergy of Ag In Situ Anchored on AgNb1–xTaxO3 Solid Solutions as an Efficient and Durable Catalyst toward Nitrobenzene Reduction: Uncovering the Relevance of the Electronic Structure, Active Sites, and Catalytic Activity

“…The decrease of cell volume likely results in the diminishing grain size. In many oxide systems, like TiO 2 , CuO, NaTaO 3 , BaTiO 3 , and ZnWO 4 , it was reported that both surface modification and substitution also play critical roles in modulating the crystalline structure and morphology size. − Typically, it is structural relaxation or contraction and atomic anisotropy that results in lattice variation. The phenomenon is matched well with experimental data and is consistent with the previous report.…”