Ammonolysis-free synthesis of La2O2CN2 by cyanamidation of La(OH)3 using urea, and its photoluminescence properties
Mixed anion compound
A facile method was successfully developed to prepare lanthanum oxycyanamide, La2O2CN2. Urea was selected as a cyanamidation agent, instead of gaseous NH3 with graphite containers, to achieve a safe and simple synthetic strategy. Through the optimization of reaction conditions, including content of urea and heat-treatment temperature, single-phase La2O2CN2 could be obtained without any impurities. We also prepared a La2O2CN2:Eu3+ phosphor. The Eu3+-doped La2O2CN2 matrix showed a red emission. Furthermore, in comparison with La2O3:Eu3+, the photoluminescence excitation bands corresponding to the Eu3+–ligand charge transfer region were broadened. These results suggested that La2O2CN2 prepared via the urea route will offer superb application prospects for photoluminescence materials such as white light-emitting diodes.
This work was supported by JSPS KAKENHI Grant Numbers JP17H05483 and JP17H03392. This work was partly supported by the Center for Functional Nano Oxide at Hiroshima University, Japan.
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