Trivalent rare-earth-activated luminescent materials have attracted a lot of attention due to their fascinating optical properties and broad range of applications. In this study, polycrystalline Sm and Eu-doped LiMgPO₄ luminescent materials were synthesized using a solid-state reaction technique. The crystalline structures, morphological features, and optical characteristics of the synthesized materials were thoroughly investigated using x-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM) and UV–vis spectroscopy. The Rietveld refinement analysis confirmed the phase purity of synthesized phosphors. In addition, the strain induced owing to the incorporation of trivalent rare-earth ions and crystallite sizes of each synthesized material was estimated using the Williamsons-Hall (W-H) and modified Debye-Sherrer equations. The estimated results of the microstrain were reported to be 0.0010, 0.0023 and 0.0020. Subsequently, as a consequence of distinct peak profile options, the projected average crystallite size by both approaches was distinct. The UV–vis spectroscopy analysis reveals that Sm and Eu doped materials exhibit absorption bands around 402 nm and 396 nm and depicts the declining band gap values. The Photoluminescence (PL) spectra at 402 nm and 395 nm excitation wavelengths exhibited the distinctive emissions of both Sm³⁺ (⁴G_5/2 → ⁶H_7/2) and Eu³⁺ (⁵D₀ → ⁷F₂) ions emanating due to the intra-configurational f - f and 4 f − 4 f transitions. Finally, the CIE diagram explicitly demonstrates that the Sm and Eu-modified materials reveal their exceptional color purity. McCamy’s approach was used to determine various parameters of trivalent rare-earth doped materials. The correlated color temperature ( TCCT ) and their coordinates TCCT (ζ, β) was found to be 2287 K, 1900 K, 0.281, 0.632, and 0.302, 0.681 respectively. Temperature-dependent emission spectra exhibit excellent color and thermal stability at high temperatures. The obtained results in this study indicate that the synthesized luminescent materials can potentially be used in white light-emitting diode applications.

中文翻译：

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三价稀土离子掺杂LiMgPO4的光学和光致发光性能

三价稀土激活发光材料因其迷人的光学性质和广泛的应用而引起了广泛的关注。本研究采用固相反应技术合成了多晶Sm和Eu掺杂的LiMgPO ₄发光材料。使用 X 射线衍射 (XRD)、傅里叶变换红外光谱 (FTIR)、场发射扫描电子显微镜 (FE-SEM) 和紫外可见光谱对合成材料的晶体结构、形态特征和光学特性进行了深入研究。 Rietveld 精修分析证实了合成荧光粉的相纯度。此外，使用 Williamsons-Hall (WH) 和修正的 Debye-Sherrer 方程估计了由于掺入三价稀土离子和每种合成材料的微晶尺寸而引起的应变。据报告，微应变的估计结果为 0.0010、0.0023 和 0.0020。随后，由于不同的峰轮廓选项，两种方法预测的平均微晶尺寸是不同的。紫外可见光谱分析表明，Sm 和 Eu 掺杂材料在 402 nm 和 396 nm 附近表现出吸收带，并描述了带隙值的下降。 402 nm 和 395 nm 激发波长处的光致发光 (PL) 光谱表现出 Sm ³⁺ ( ⁴ G _5/2 → ⁶ H _7/2 ) 和 Eu ³⁺ ( ⁵ D ₀ → ⁷ F ₂ ) 离子的独特发射由于构型内 f - f 和 4 f - 4 f 转变而产生。最后，CIE 图明确表明 Sm 和 Eu 改性材料显示出其卓越的色纯度。 McCamy 的方法用于确定三价稀土掺杂材料的各种参数。相关色温（ 时间相关色温 ）及其坐标 时间相关色温 (δ,β) 分别为 2287 K、1900 K、0.281、0.632 和 0.302、0.681。温度相关的发射光谱在高温下表现出优异的颜色和热稳定性。本研究获得的结果表明，合成的发光材料有可能用于白光发光二极管应用。