A Technique to Fabricate La₂O₂CN₂:Tb³⁺ Nanofibers and Nanoribbons with the Same Morphologies as the Precursors

Abstract

Terbium(III)-doped lanthanum dioxymonocyanamide (La 2 O 2 CN 2 :Tb 3+ ) nanofibers and nanoribbons were fabricated, by the cyanamidation technique, from precursor La 2 O 3 :Tb 3+ nanofibers and nanoribbons prepared by electrospinning. The morphology of the final products were the same as those of the precursors. X-ray powder diffraction analysis indicated that the crystal phase of La 2 O 2 CN 2 :Tb 3+ is tetragonal in space group I4/mmm. SEM analysis revealed that the thickness and width of the La 2 O 2 CN 2 :Tb 3+ nanoribbons is about 184 nm and 3.53 Ϯ 0.37 μm, respectively, and the diameter of the La 2 O 2 CN 2 :Tb 3+ nanofibers is 175.87 Ϯ 16.23 nm at a 95 % confidence level. When excited with a 274 nm ultraviolet light source, the La 2 O 2 CN 2 :Tb 3+ nanostructures emit predominantly at 543 nm; this emission originates from the 5 D 4 Ǟ 7 F 5 energy level transition of the [a]

Luminescent properties of novel red-emitting phosphor: Gd_2O_2CN_2:Eu^3+

“…Meanwhile, the emitted radiation of Gd 2 O 3 :Eu 3+ is dominated by the red emission peak at 612 nm [21] . From the predominant peaks at 614 and 626 nm, it can be further proved the formation of the oxycyanamide host [13][14][15] . Some weak peaks can be observed at 580 nm, 590 nm, 594 nm and 653 nm, corresponding to the forbidden transition 5 D 0 → 7 F 0 (580 nm) and the magnetic dipole transitions 5 D 0 → 7 F 1 (590 nm and 594 nm) and 5 D 0 → 7 F 3 (653 nm).…”

“…Rare earth dioxymonocyanamides (RE 2 O 2 CN 2 , RE=La, Ce, Pr, Nd, Sm, Eu, Gd) [11] were prepared by nitriding a mixture of rare earth oxide in flowing ammonia at 950 °C. The luminescent properties of RE 2 O 2 CN 2 :M 3+ (Ln = Y, Gd and La, M 3+ = Tb 3+ , Eu 3+ , Pr 3+ , Er 3+ and Er 3+ /Tb 3+ ) have been previously studied [11][12][13][14] . Eu 3+ doped Gd 2 O 2 CN 2 was firstly prepared by sol-gel method by Takeda et al, but the luminescence intensity was weak because of its low crystallinity and the suppression of concentration quenching was not recognized because of the presence of impurities for high Eu-doping concentration [15] .…”

Mechanistic Insights on the Formation of a Carbodiimide Ion from Urea in La2O2NCN Synthesis Based on the “Proanion” Strategy

“…15−23 23 Generally, such metal (oxy)carbodiimides are synthesized using the solution process, 8,24 solid-state metathesis method, 7,14,25 or calcination of precursors under a stream of NH 3 gas. 12,13,[15][16][17][18]21,22 Although solid-state metathesis is straightforward, it occasionally necessitates vacuum sealing in ampules and is unsuitable for systems with easily reducible metal elements. The reliance on a highly toxic and expensive reagent is a serious problem of the ammonia gas method, which is compounded by the need for a prolonged reaction time and a high temperature.…”

A novel strategy to achieve NaGdF4:Eu3+ nanofibers with color‐tailorable luminescence and paramagnetic performance

“…[35][36][37] Hence, the fabrication of NaGdF 4 :RE 3+ nanofibers becomes temporally urgent. Electrospinning technique is a direct and convenient process making uniform and ultralong 1D nanomaterials, such as nanofibers, [38][39][40][41][42] nanobelts, [43][44][45] hollow nanofibers, [46][47][48][49] Janus nanofibers, 50 ribbon-shaped coaxial nanocables, 51 and Janus nanobelts. 4,52 However, as far as we know, the final products are often oxides after calcining the electrospun composite nanomaterials.…”