From metals to nitrides - Syntheses and reaction details of binary rare earth systems
作者:Tobias Dierkes、Julian Plewa、Thomas Jüstel
DOI:10.1016/j.jallcom.2016.09.139
日期:2017.2
Abstract The reaction of several rareearth ( RE ) metals ( RE = Y, La, Ce, Pr, Eu, Gd, Tb and Lu) with gaseous hydrogen and the subsequent reaction of the resulting hydrides with nitrogen gas have been investigated by means of a combinatory approach of thermogravimetric and differential thermal analysis. Focus was laid on the fabrication of bulk material, in quantities suitable as precursor materials
Photoluminescence properties of rare-earth activated BaSi7N10
作者:Y.Q. Li、A.C.A. Delsing、R. Metslaar、G. de With、H.T. Hintzen
DOI:10.1016/j.jallcom.2009.08.019
日期:2009.11
3+ -activated BaSi7 N 10 have been studied. The transitions of f ↔ d of the Eu 2+ and Ce 3+ ions occur at relatively high energies for nitrides which are principally attributed to weak bonding strength of Ba–N and small crystal field splitting of 5d excitation levels of Eu 2+ and Ce 3+ due to a large Ba crystallographic site in BaSi7 N 10 . As a result, it was found that BaSi7 N 10 :Eu 2+ showed
摘要 研究了Eu 2+ -、Ce 3+ - 和Tb 3+ 活化的BaSi 7 N 10 的光致发光特性。对于氮化物,Eu 2+ 和 Ce 3+ 离子的 f ↔ d 的跃迁发生在相对较高的能量下,这主要归因于 Ba-N 的弱键合强度和 Eu 2+ 和 Ce 的 5d 激发能级的小晶体场分裂3+ 由于 BaSi 7 N 10 中的大 Ba 结晶位点。结果,发现BaSi 7 N 10 :Eu 2+ 在约475nm处显示蓝色发射,其源于UV激发时Eu 2+ 的4f 6 5d 1 → 4f 7 跃迁。而BaSi 7 N 10 :Ce 3+ 、Li + 则表现出UV-蓝色发射,在大约400 nm 处有最大值,这是由Ce 3+ 的5d → 4f 跃迁引起的。在 BaSi 7 N 10 :Tb 3+ , Li + 中,Tb 3+ 的发光光谱主要是由 5 D 4 → 5 FJ ( J = 3, 4,
Magnetocaloric properties of TbN, DyN and HoN nanopowders prepared by the plasma arc discharge method
作者:K. P. Shinde、S. H. Jang、J. W. Kim、D. S. Kim、M. Ranot、K. C. Chung
DOI:10.1039/c5dt03528g
日期:——
We report for the first time the synthesis of nanopowders of TbN, DyN and HoN crystallized in a cubic structure by the plasma arc discharge (PAD) method and investigate their magnetocaloric properties for magnetic refrigeration applications.
under UV light excitation. Thus a colortunable emission from blue to green was obtained via controlling the doping concentration of Tb3+. In addition, the mechanism of energy transfer, efficiency of energy transfer, chromaticity coordinates and thermal stability of these phosphors were investigated. The results indicated that the Ce3+,Tb3+ co-activated LaSi3N5 phosphors with color-tunable blue-green emission
通过高温固态法获得了一系列新的发射蓝绿色的LaSi 3 N 5:Ce 3+,Tb 3+荧光粉。研究了Ce 3+到Tb 3+的晶体结构,光致发光性质和能量转移。使用Rietveld结构细化方法证实了掺杂的离子Ce 3+和Tb 3+占据与La 3+相同的晶体学位置。这些磷光体的发射光谱由归因于Ce 3+的d–f跃迁的蓝色发射带以及归因于Tb 3+发射的几条清晰的线组成在紫外线激发下。因此,通过控制Tb 3+的掺杂浓度,获得了从蓝色到绿色的颜色可调发射。此外,还研究了这些荧光粉的能量转移机理,能量转移效率,色度坐标和热稳定性。结果表明,具有颜色可调的蓝绿色发射和高量子效率的Ce 3+,Tb 3+共激活的LaSi 3 N 5磷光体可能具有紫外白光LED的潜力。
Synthesis, structure and properties of RNiBN (R = rare-earth elements)
作者:Shi-jie Song、Bai-Zhuo Li、Qin-Qing Zhu、Zhi Ren、Guang-Han Cao
DOI:10.1016/j.jallcom.2023.172491
日期:2024.1
We report the structural and physical properties of new nitridoborates NiBN ( = Nd, Sm, Gd, Tb, Dy, Ho, and Er). These compounds crystallize in a tetragonal LaNiBN-type structure with two-dimensional NiB and N layers. The physical properties measurements indicate that they are antiferromagnetic metals. For = Gd and Ho, a successive magnetictransition was observed below N é el temperature, possibly
我们报告了新型硝基硼酸盐 NiBN(= Nd、Sm、Gd、Tb、Dy、Ho 和 Er)的结构和物理性质。这些化合物结晶为具有二维 NiB 和 N 层的四方 LaNiBN 型结构。物理特性测量表明它们是反铁磁金属。对于 = Gd 和 Ho,在 Néel 温度以下观察到连续的磁转变,这可能与 Ruderman-Kittel-Kasuya-Yosida 相互作用导致的自旋重新定向有关。在 = Er 和 Ho 化合物中测量到巨磁热效应,该效应与场诱导的从反铁磁态到铁磁态的一级变磁转变有关。我们的结果表明 NiBN(= Er 和 Ho)可能是低温磁制冷的有希望的候选者