In this paper hexagonal trivalent lanthanide ions (Ln³⁺) doped β-NaYF₄ microparticles were synthesized by a facile hydrothermal method. The structure, morphology and composition of the microparticles were confirmed by XRD, SEM, EDS. Multicolor luminescence was observed. The up-conversion(UC) and down conversion emission intensity of β-NaYF₄: Ln³⁺ (Ln³⁺=Er³⁺, Eu³⁺) microparticles and the red-emission of β-NaYF₄：Er³⁺/Eu³⁺ microparticles were increased. The La³⁺ ions doped the samples enhancing energy transfer between the Ln³⁺ ions by altering the crystal field symmetry around Ln³⁺ is described.

中文翻译：

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的增强的红色发光β-NaYF ₄：铒³⁺ / EU ³⁺经由与拉能量转移微粒³⁺掺杂

本文六边形的三价镧系元素离子（LN ³⁺）掺杂β-NaYF _4个微粒通过一个浅显的水热法合成。通过XRD，SEM，EDS证实了微粒的结构，形态和组成。观察到多色发光。上转换（UC）和向下转换发射强度β-NaYF ₄：LN ³⁺（LN ³⁺ =尔³⁺，Eu的³⁺）微粒和红色发光β-NaYF ₄：铒³⁺ / Eu ³⁺微粒增加。La ³⁺离子掺杂了样品，从而增强了Ln ³⁺之间的能量转移描述了通过改变Ln ³⁺周围的晶体场对称性产生的^离子。