VUV spectroscopic properties of rare-earth (RE³⁺= Eu, Tb, Tm)-dopedAZr₂(PO₄)₃(A⁺= Li, Na, K) type phosphate

Abstract

The excitation spectra of pure and rare-earth (RE3+ = Eu, Tb, Tm)-doped AZr2(PO4)3 (A+ = Li, Na, K) in the vacuum ultraviolet (VUV) regions are investigated. The results indicate that these samples show strong absorption in the VUV range. The band ranging from 130 to 160 nm is due to the absorption band of host lattice or PO4 groups; the band at 160–200 nm is related to the charge transfer (CT) transition of O–Zr. For Eu3+-doped samples, the weak band in the excitation spectra at about 208 nm is related to the CT band of O2−–Eu3+. As for Tb3+-doped samples, the strong band at 225 nm and the weak band at 261 nm in the excitation spectra are assumed to the spin-allowed and spin-forbidden f–d transitions (4f8→ 4f75 d1) of Tb3+. However, there is no obvious band of CT of O2−–Tm3+ in the Tm3+-doped samples.

A Novel Facile Room Temperature Chemical Lithiation for Reduction of Eu3+ in NASICON Crystal Structure

“…[14][15][16] Thus, some of this NASICON type materials were found to be good hosts for novel luminescent materials. The VUV luminescence properties of RE 3+ -doped AZr 2 (PO 4 ) 3 (A + = Li, Na, K) [17] [5] were demonstrated as novel potential blue luminescent materials.…”

“…-group in structure of NASICON structure exhibits great VUV luminescence properties, [17] ions via electrochemical lithium insertions. [7] Chemical lithiation using nBu-Li (2.5 m in hexane) at room temperature is better for Eu 2+ -doped luminescent materials synthesis and research.…”

“…Thus, some of this NASICON type materials were found to be good hosts for novel luminescent materials. The VUV luminescence properties of RE 3+ ‐doped A Zr 2 (PO 4 ) 3 ( A + = Li, Na, K)17 have been investigated. Eu II 1/2 Zr 2 (PO 4 ) 3 6 and Eu 2+ ‐doped M II 1/2 Zr 2 (PO 4 ) 3 ( M II = Ca, Sr, Ba)5 were demonstrated as novel potential blue luminescent materials.…”

“…This type crystal structure shows great features for novel luminescent materials: (1) The [Zr 2 (PO 4 ) 3 ] – group in structure of NASICON structure exhibits great VUV luminescence properties,17 (2) the 3D rigid [Zr 2 (PO 4 ) 3 ] – network is quite stable, (3) large average distance (>5 Å) between RE 3+ ions will reduce the luminescence concentration quenching, and (4) the luminescence properties of Eu ions in this type crystal structure can be tuned by modifying the chemical elements forming the 3D [Zr 2 (PO 4 ) 3 ] – network 5,6. Thus, utilizing these features of NASICON crystal structures, Saradhi et al synthesized a single‐phased phosphor containing both Eu 2+ and Eu 3+ ions via electrochemical lithium insertions 7.…”

Combustion synthesis and optimization of Tb3+-doped AZr2(PO4)3(A+= Li, Na, K) phosphors for mercury-free lamp and plasma display panels application

“…The VUV studies of zirconium containing phosphors like ZrP 2 O 7 , CaZr(PO 4 ) 3 and NaZr 2 (PO 4 ) 3 have been investigated by Kaneyoshi [8]. Recently Zhi-Jun Zhang et al reported the preparation of Tb 3+ doped AZr 2 (PO 4 ) 3 by solid-state reactions at high temperature with feasibility as a green phosphor of PDP, which can be easily excited by 172 nm [9].…”