Unique properties of ZnTiF6・6H2O:Mn4+ red-emitting hexahydrate phosphor
Unique properties of ZnTiF6・6H2O:Mn4+ red-emitting hexahydrate phosphor
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ZnTiF6·6H2O:Mn4+发红光六水合物荧光粉的独特性能
DOI：
10.1016/j.jlumin.2016.12.028
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
and S. Adachi
中科院分区：
文献类型：
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作者：
R. Hoshino;S. Sakurai;T. Nakamura;and S. Adachi
采用x射线衍射（XRD）测量、光致发光（PL）分析、PL激发光谱、电子顺磁共振和拉曼散射光谱等方法研究了ZnTiF 6·6h2o: mn4 +红色六水荧光粉的结构和发光性能。ZnTiF 6·6h2o: mn4 +荧光粉在低于~ 150℃或高于~ 150℃的温度下（T a）退火后，XRD谱线和PL谱线发生了显著变化。在低于~ 150℃的温度下加热后，六水荧光粉的结构发生了相变，可能从室温稳定的三角对称（R 3¯）转变为低温稳定的单斜对称（P 21 / C）。令人惊讶的是，当荧光粉在低温恒温器中真空抽真空时，获得了相似的XRD和PL数据。这也是本研究的一个新发现，并得到了拉曼散射数据的支持。将样品置于室温环境中，部分脱水状态恢复为再水合状态。在温度为~ 200℃以上的退火将六水荧光粉转变为具有三角形R 3¯m对称性的脱水荧光粉（ZnTiF 6: mn4 +），并给出了与六水荧光粉明显不同的PL光谱。通过将样品暴露在可见光-近紫外光下，还观察到ZnTiF 6·6h2o: mn4 +的光致发光效率下降，这可以通过Mn离子的光氧化和/或歧化反应来解释。
The structural and luminescence properties of ZnTiF 6· 6H 2 O: Mn 4+ red-emitting hexahydrate phosphor were investigated using X-ray diffraction (XRD) measurement, photoluminescence (PL) analysis, PL excitation spectroscopy, electron paramagnetic resonance, and Raman scattering spectroscopy. The ZnTiF 6· 6H 2 O: Mn 4+ phosphor exhibited remarkable change in the XRD traces and PL spectra after thermal annealing at temperatures (T a) below or above∼ 150° C. After heating below∼ 150° C, the hexahydrate phosphor showed structural phase transition, probably from the room-ambient stable trigonal symmetry (R 3¯) to the low-temperature stable monoclinic symmetry (P 2 1/c). Surprisingly, similar XRD and PL data were obtained when the phosphor was vacuum-evacuated in a cryostat. This is also a novel finding of the present work and is supported by the Raman scattering data. The partially dehydrated state returned to the rehydrated state by putting the sample in room ambient. Annealing above a T a of∼ 200° C changed the hexahydrate phosphor to the dehydrated one (ZnTiF 6: Mn 4+) with the trigonal R 3¯ m symmetry and gave clearly different PL spectra from its hexahydrate counterpart. Photo-induced degradation in the PL efficiency of ZnTiF 6· 6H 2 O: Mn 4+ was also observed by exposing the samples to visible–near-UV light and could be explained by the photooxidation and/or disproportionation reactions of the Mn ions.