The radiative transition probability is a fundamental property for optical transitions. Extensive research, theoretical and experimental, has been conducted to establish the relation between the photonic environment and electric dipole (ED) transition probabilities. Recent work shows that the nanocrystal (NC)-cavity model accurately describes the influence of the refractive index n on ED transition rates for emitters in NCs. For magnetic dipole (MD) transitions, theory predicts a simple n³ dependence. However, experimental evidence is sparse and difficult to obtain. Here we report Eu³⁺-(with distinct ED+MD transitions) and Gd³⁺-(MD transitions) doped β-NaYF₄ NC model systems to probe the influence of n on ED and MD transition probabilities through luminescence lifetime and ED/MD intensity ratio measurements. The results provide strong experimental evidence for an n³ dependence of MD transition probabilities. This insight is important for understanding and controlling the variation of spectral distribution in emission spectra by photonic effects.

中文翻译：

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磁偶极跃迁的光子效应

辐射跃迁概率是光学跃迁的基本属性。已经进行了广泛的理论和实验研究，以建立光子环境与电偶极子（ED）跃迁概率之间的关系。最近的工作表明，纳米晶体（NC）腔模型可以准确地描述折射率n对NC中发射极的ED跃迁速率的影响。对于磁偶极（MD）跃迁，理论上预测了简单的n ³依赖性。但是，实验证据稀少且难以获得。在这里，我们报告的Eu ³⁺ - （具有鲜明ED + MD转换）和Gd ³⁺ - （MD转换）掺杂β-NaYF ₄NC模型系统通过发光寿命和ED / MD强度比测量来探究n对ED和MD转变概率的影响。结果为MD转移概率n ³依赖性提供了有力的实验证据。该见解对于理解和控制由光子效应引起的发射光谱中光谱分布的变化非常重要。