Tetra‐valent manganese (Mn⁴⁺) has been regarded as an efficient non‐rare‐earth red‐light emitting ion, which has stimulated continued search of robust hosts and efficient synthetic methods to stabilize Mn⁴⁺ centers with strong photoluminescence. In this work, we demonstrate a facile synthetic method for Mn⁴⁺ doped glass‐ceramic (GC) based on crystallization‐induced oxidation state change in an oxide glass. The parent glass with a formula of LiNaGe₄O₉ is fabricated by melt‐quenching and crystallization is induced by thermal treatment in air. Oxidation of Mn²⁺ in glass to Mn⁴⁺ in the GC is confirmed by both optical spectroscopy and electron paramagnetic resonance (EPR) measurements. After thermal treatment, the characteristic reddish photoluminescence (PL) of Mn²⁺ in the glass centered at 611 nm disappears and a strong photoluminescence peak at 660 nm attributed to Mn⁴⁺ is observed. The conversion to Mn⁴⁺ after crystallization in the examined system may have strong implications for synthesis of Mn⁴⁺ doped phosphors which always requires rigorous control of the redox equilibrium during synthesis.

中文翻译：

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LiNaGe4O9玻璃陶瓷中Mn2 +→Mn4 +的晶化价态变化

四价锰（Mn ⁴⁺）被认为是一种有效的非稀土类红色发光离子，它刺激了人们继续寻找稳定的基质和有效的合成方法来稳定具有强光致发光的Mn ⁴⁺中心。在这项工作中，我们基于氧化物玻璃中晶化引起的氧化态变化，论证了一种用于Mn ⁴⁺掺杂玻璃陶瓷（GC）的简便合成方法。分子式为LiNaGe ₄ O ₉的母玻璃是通过熔融淬火制成的，并且通过在空气中进行热处理来诱导结晶。将玻璃中的Mn ²⁺氧化为Mn ⁴⁺气相色谱法和电子顺磁共振法（EPR）均证实了GC中的HPLC。在热处理之后，以611nm为中心的玻璃中的Mn ²⁺的特征性红光发光（PL）消失，并且观察到归因于Mn ^4+的在660nm处的强光致发光峰。在所考察的系统中，结晶后转化为Mn ⁴⁺可能会对Mn ⁴⁺掺杂的磷光体的合成产生重大影响，在合成过程中始终需要严格控制氧化还原平衡。