Morphological study of Sr2CeO4 blue phosphor with fine particles

Abstract

Recebido em 31/7/03; aceito 6/2/04; publicado na web em 17/6/04Morphological and spectroscopic studies of Sr 2 CeO 4 blue phosphor in the form of fine particles prepared from a powdered multicomponent precursor, via a combustion method, are reported. Samples were also prepared through a solid-state reaction and from a polymeric precursor for comparison. Citric acid or glycine as fuels in the combustion method lead to a mixture which is heated at 950 o C for 4 h, resulting in spheroidal particles with a diameter between 250-550 nm. Samples from the polymeric precursor result in spheroidal particles (350-550 nm) and from the solid-state reaction in irregular particles (~ 5 µm). Therefore, the combustion method is adequate for preparation of Sr 2 CeO 4 in the form of spherical fine particles.

Synthesis and characterization of Sr2CeO4 phosphor: Positive features of sol–gel technique

“…A blue emitting phosphor, Sr 2 CeO 4 , has therefore been synthesized by combinatorial material synthesis by Danielson et al [2]. Subsequently other synthesis techniques like solid state reaction [3], chemical co precipitation process [4], microwave calcination technique [5], ultrasonic spray pyrolysis technique [6], pulsed-laser deposition procedure [5,7], Pechini's method [8], citrate-gel method [9], combustion method [10], microwave-accelerated hydrothermal technique [11], polymer synthesis [12], wet chemical method [13], emulsion liquid membrane system [14,15], sol-gel by single alkoxide precursor [16], laser ablation [17], microemulsion method [18] and carbonate precursor [19] have been tried to synthesize the same material. Some of the above techniques requires higher firing temperature, i.e.…”

“…Some of the above techniques requires higher firing temperature, i.e. above 1200 1C [4,7], whereas all the other synthesis methods mentioned above state that the compound formation was done only at 900-1100 1C [2,3,5,6,[8][9][10][11][12][13][14]. Some of these techniques of low firing temperature require firing for longer durations at elevated temperatures, while some of them require very expensive and not easily available starting materials [15].…”

Luminescence properties of sol–gel derived Sr2(Ce1−Sn )O4 blue phosphors

“…4(a)-(c). The excitation bands of Sr 2 (Ce 1−x Sn x )O 4 (x = 0.01 and 0.03) and that of pure Sr 2 CeO 4 phosphor showed similar patterns [8,21,22]. On the contrary, the intensity of the high-energy peak (at around 296 nm) was lower than that of the low-energy peak (at around 347 nm) when x was increased to 0.05 and 0.07.…”

Luminescent and morphological study of Sr2CeO4 blue phosphor prepared from oxalate precursors

“…The combustion method [17,18] and a polymer sol-gel route [19,20] involving polyetileglycol (PEG-2000) [21] have also been used.…”