Remarkable red-shift of upconversion luminescence and anti-ferromagnetic coupling in NaLuF₄:Yb³⁺/Tm³⁺/Gd³⁺/Sm³⁺ bifunctional microcrystals

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• 作者：Shigang HU ((胡仕刚))^a ; Yunxin LIU ((刘云新))^b ; ^{lyunxin@163.com" class="auth_mail" title="E-mail the corresponding author} ; Xiaofeng WU ((吴笑峰))^a ; Zhijun TANG ((唐志军))^a ; Zhiming LI ((李志明))^c ; Huanyuan YAN ((颜焕元))^d ; Zenghui CHEN ((陈增辉))^b ; Pan HU ((胡 盼))^a ; Yi YU ((余 意))^a
• 关键词：upconversion luminescence ; magnetic property ; bifunctional ; rare earth ; doping
• 刊名：Journal of Rare Earths
• 出版年：2016
• 出版时间：February 2016
• 年：2016
• 卷：34
• 期：2
• 页码：166-173
• 全文大小：1352 K

文摘

Lanthanide doped bifunctional materials are potentially important for developing multifunctional devices. Here, NaLuF₄:Yb³⁺/Tm³⁺/Gd³⁺/Sm³⁺ optical-magnetic bifunctional microcrystals were successfully synthesized by hydrothermal method, which could emit ∼480 nm blue light from the ¹G₄→³H₆ electronic transition and ∼800 nm infrared light from the ³H₄→³H₆ electronic transition of Tm³⁺ ion, under the excitation of 980 nm infrared light. By doping Sm³⁺ ion into NaLuF₄:Yb³⁺/Tm³⁺/Gd³⁺, the infrared emission peak centered at 800 nm would shift obviously to longer wavelength. This indicated that Sm³⁺ ion could efficiently tune the energy level gaps of Tm³⁺ ions in NaLuF₄ host which was demonstrated based on the crystal field theory. In addition, these NaLuF₄:Yb³⁺/Tm³⁺/Gd³⁺/Sm³⁺ microcrystals presented unique ferromagnetic property instead of usually reported paramagnetic property. Importantly, the ferromagnetic property decreased with increasing the concentration of Gd³⁺ ion. This was in good agreement with Swift's theoretical investigation that the coexistence of light rare earth (Gd³⁺) and heavy rare earth (Yb³⁺/Tm³⁺) would lead to the anti-ferromagnetic coupling in the sub-lattices.