Analysis of the absorption and luminescence spectra of U3+:Cs2NaYBr6 single crystals
作者:M Karbowiak、E Zych、P Dereń、J Drożdżyński
DOI:10.1016/s0301-0104(02)01024-8
日期:2003.2
Uranium(3+) doped Cs2NaYBr6 singlecrystals with a 2.1 and 0.09 mol% U3+ concentration have been obtained by the Bridgman–Stockbarger method. The U3+ ions replaced the Y3+ ions at an octahedral site of Oh symmetry. Luminescencespectra of the crystal were recorded at 4.2 K. The emission bands observed in the visible and near infrared regions have been assigned to transitions from the lowest components
通过Bridgman–Stockbarger方法获得了U 3+浓度为2.1和0.09 mol%的掺铀(3+)的Cs 2 NaYBr 6单晶。在O h对称的八面体位置,U 3+离子取代了Y 3+离子。晶体的发光光谱在4.2 K下记录。在可见光和近红外区域观察到的发射带已分配为从的最低组分和多重峰到基态的晶体场组分的跃迁。吸收光谱记录在3900–35,000 cm -1范围为4.2K。对这些光谱的分析能够分配28个能级,这些能级与经验哈密顿量的七个参数相符,这些参数代表原子和晶体-场相互作用的组合,均方根偏差为43 cm -1。已经测量了最突出的振动特征的能量,并将其分配给UCl 6 3-的特定振动模式或晶格模式。在14,000 cm -1以上,观察到与电偶极子相关的振动跃迁,允许5f 3 –5f 2 6d 1跃迁。悬而未决的零声子线伴随着许多振动级数与偶数S 1的组合(1g)模式。
Magnetic and Crystal Structure Determination of K2UBr5
作者:Karl Krämer、Lukas Keller、Peter Fischer、Bernd Jung、Norman N. Edelstein、Hans-U Güdel、Gerd Meyer
DOI:10.1006/jssc.1993.1087
日期:1993.3
Magnetic susceptibility measurements show an antiferromagnetic ordering phenomenon for K2UBr5. There is a broad maximnm in the χ versus T curve at about 10 K. Aiming at the determination of the magneticstructure of K2UBr5, powder neutron diffraction investigations were performed. The nuclear structure of K2UBr5 (K2PrCl5 type of structure) was refined at 15 K in the paramagnetic state. The magnetic
Uranium Cyanides from Reactions in Liquid Ammonia Solution
作者:Tim Graubner、Stefan S. Rudel、Sergei I. Ivlev、Antti J. Karttunen、Florian Kraus
DOI:10.1002/ejic.202400041
日期:——
So far there are only very few uranium cyanides. Three novel uranium cyanides have been obtained from reactions of uranium halides with cyanides in liquid ammonia as a solvent.