2024-03-28T17:31:39Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/748092022-11-17T02:08:08Zhdl_2115_20045hdl_2115_139Red-emission over a wide range of wavelengths at various temperatures from tetragonal BaCN2:Eu2+Masubuchi, YujiNishitani, SayakaHosono, AkiraKitagawa, YuukiUeda, JumpeiTanabe, SetsuhisaYamane, HisanoriHiguchi, MikioKikkawa, ShinichiA new polymorph of BaCN2 was obtained via a simple nitridation reaction of BaCO3 under an NH3 flow at 900 1C. The product was analyzed via single crystal X-ray diffraction and infrared spectroscopy, and it was found to have a tetragonal I4/mcm crystal structure (space group no. 140) with a = 0.60249(4) nm and c = 0.71924(5) nm. In this structure, each Ba2+ cation is situated in the square antiprism of N atoms of NCN(2-)anionic groups. Eu2+ doped BaCN2 can be excited by irradiation of blue and green light (from 400 to 550 nm), and it generates an intense red emission peak at 660 nm with a quantum efficiency of 42% in response to 465 nm excitation at room temperature. The peak emission wavelength varies over an extremely wide range of temperature, from 640 nm at 500 K to 680 nm at 80 K, and this red-shift with decreasing temperature is attributed to a unit cell shrinkage that results in significant crystal field splitting of the 5d energy levels of the Eu2+ ions.Royal Society of ChemistryJournal Articleapplication/pdfhttp://hdl.handle.net/2115/74809https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/74809/1/JMaterChemC2018-6370-6377.pdf2050-7526Journal of materials chemistry C624637063772018-06-28enginfo:doi/10.1039/c8tc01289jauthor