Oxalic Acid-Assisted Hydrothermal Synthesis and Luminescent of Hexagonal NaYF₄:Ln³⁺ (Ln = Sm, Eu, Yb/Er) Micro/Nanoplates

Figure 2

(a) Typical FE-SEM images of NaYF₄:Eu samples; (b) local magnified FE-SEM images; (c) SAED and (d) HRTEM of NaYF₄:Eu samples obtained at pH = 6, = 0.3, 200°C for 24 h.

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