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Synthesis and Luminescent Properties of a New Eu 3+ ‐Doped Li 1+ x ( Ta 1− z Nb z ) 1− x Ti x O 3 Red Phosphor
Author(s) -
Nakano Hiromi,
Ozono Keita,
Hayashi Hiroyuki,
Fujihara Shinobu
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2012.05372.x
Subject(s) - photoluminescence , phosphor , luminescence , analytical chemistry (journal) , doping , materials science , sintering , ion , superstructure , crystallography , chemistry , metallurgy , physics , optoelectronics , organic chemistry , chromatography , thermodynamics
A new red phosphor based on the Li 1+ x ( Ta 1− z Nb z ) 1− x Ti x O 3 ( LTNT , 0.05 ≤ x ≤ 0.25, 0 ≤ z ≤ 0.625) solid solution as a host material has been synthesized. This host material is known as an M ‐phase and has a superstructure similar to that of the Li 1+ x − y Nb 1− x −3 y Ti x +4 y O 3 ( LNT ) solid solution. An Eu 3+ ‐doped LTNT has been prepared by sintering at 1413 K–1433 K for 24 h in a conventional electric furnace; the optimal sintering temperature for obtaining higher photoluminescence ( PL ) intensity was found to be 1423 K. Interestingly, bright red emission due to the hypersensitive 5 D 0 ‐ 7 F 2 transition in Eu 3+ was observed under direct excitation of the 4 f electron at 541 ( 7 F 0 ‐ 5 D 1 ) or 398 nm ( 7 F 0 ‐ 5 L 6 ). The PL intensity of the LTNT phosphor was found to be dependent on the concentration of Eu 3+ , Ti 4+ , Nb 5+ , and Ta 5+ ions. The PL intensity upon excitation at 541 nm was higher than that at 398 nm with decreasing Nb 2 O 5 content in the LTNT host material. The highest PL intensity was achieved for the composition Li 1.11 Ta 0.89 Ti 0.11 O 3 doped with 2.5 wt% of Eu 2 O 3 .