Due to an unintended oversight, this Reply to Comment was published online on October 26, 2020, prior to the Comment also being available online. The Comment was published online on November 6, 2020. In a recent Comment, Yu et al. proposed that the emission observed by us in Mn⁴⁺:Na₄Mg(WO₄)₃ phosphors stems from Mn²⁺ rather than Mn⁴⁺. However, that claim is not supported by the experimental data the authors present in their Comment. Careful inspection of the powder X-ray diffraction patterns (Figures S1a,b) demonstrates that the phosphors synthesized by Yu and co-workers are not phase pure. Diffraction maxima corresponding to secondary crystalline phases are evident for phosphors synthesized under air (2θ ≈ 17.3 and 27.9°) and reducing atmosphere (2θ ≈ 13.0, 17.3, 24.0, and 27.9°). The clearly evident lack of phase purity of the phosphors invalidates the claim that Mn²⁺ is incorporated into Na₄Mg(WO₄)₃ and the subsequent conclusion that the observed photoluminescence stems from Mn²⁺ doped into Na₄Mg(WO₄)₃. We would like to add that in the course of the synthesis of Na₄Mg_1–2xMn^IV_x(WO₄)₃ we attempted to dope 3 mol % of Mn²⁺ into Na₄Mg(WO₄)₃ as a control experiment; this doping level is identical to that of Yu et al. Two approaches were followed: (1) use MnCO₃ as the manganese(II) precursor and target Na₄Mg_0.97Mn^II_0.03(WO₄)₃ by heating at 675 °C under air, and (2) use MnO₂ as the manganese(IV) precursor and attempt (total or partial) reduction by heating at 675 °C under flowing H₂/N₂. However, in both cases powder X-ray diffraction demonstrated the presence of secondary crystalline phases in the final product. On this basis, we concluded that Mn²⁺ does not dope into the Na₄Mg(WO₄)₃ lattice at a 3 mol % level. Finally, we note that tetravalent manganese is EPR active and its X band spectrum consists of a sextet between 3000 and 4000 G,(1−4) similar to that of divalent manganese. Thus, the hyperfine structure of the spectrum alone cannot be used to differentiate these two species.(5) As shown in our article, the presence of Mn⁴⁺ doped into Na₄Mg(WO₄)₃ is supported by two pieces of experimental evidence: (1) first and most important, Rietveld analysis of neutron powder diffraction data, which demonstrates the absence of secondary crystalline phases across a broad range of doping levels, and (2) X-ray photoelectron spectroscopy, which shows the distinct shape of the 2p_3/2 peak, characteristic of Mn⁴⁺.(6) Additionally, we note the excellent agreement between the experimental Mg:Mn ratios determined from elemental analysis and those calculated on the basis of the theoretical formula Na₄Mg_1–2xMn^IV_x(WO₄)₃. No experimental evidence supports the presence of Mn²⁺ in the Na₄Mg(WO₄)₃ lattice. The authors declare no competing financial interest. This article references 6 other publications.

中文翻译：

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对“使用Mn ⁴⁺：Na ₄ Mg（WO ₄）₃荧光粉的频移发光温度计”的评论答复

由于意外的疏忽，本“评论回复”于2020年10月26日在线发布，随后该评论也在线发布。该评论于2020年11月6日在线发布。提出我们在Mn ⁴⁺：Na ₄ Mg（WO ₄）₃荧光粉中观察到的发射源于Mn ²⁺而不是Mn ⁴⁺。但是，作者在其评论中提供的实验数据不支持该主张。仔细检查粉末X射线衍射图（图S1a，b）表明，Yu和他的同事合成的荧光粉不是纯相。对于在空气（2θ≈17.3和27.9°）和还原性大气（2θ≈13.0、17.3、24.0和27.9°）下合成的磷光体，与次级晶相相对应的衍射最大值非常明显。明显缺乏磷光体的相纯度使Mn ²⁺掺入Na ₄ Mg（WO ₄）_3中的说法无效，随后得出的结论是，观察到的光致发光源自掺杂到Na ₄ Mg（WO _4）中的Mn ^2+。₄）₃。我们想补充一点，在钠的合成过程₄的Mg _{1-2 X}的Mn ^IV _X（WO ₄）₃我们试图原液3摩尔％的Mn ²⁺成Na ₄的Mg（WO ₄）₃作为对照实验；该掺杂水平与Yu等人的相同。两种方法如下：（1）使用碳酸锰₃为锰（II）前体和目标的Na ₄ Mg的_0.97锰^II _0.03（WO ₄）₃通过在675℃下的空气，以及（2）使用加热的MnO₂作为锰（IV）的前体，并尝试通过在流动的H ₂ / N ₂下于675°C加热进行还原（全部或部分还原）。但是，在两种情况下，粉末X射线衍射都表明最终产品中存在第二结晶相。在此基础上，我们得出结论，Mn ²⁺不会以3 mol％的水平掺杂到Na ₄ Mg（WO ₄）₃晶格中。最后，我们注意到四价锰具有EPR活性，其X谱带由介于3000到4000 G之间的六重键组成（1-4），类似于二价锰。因此，仅光谱的超精细结构不能用于区分这两种物质。（5）如本文所述，Mn的存在掺杂到Na ₄ Mg（WO ₄）_3中的⁴⁺得到两个实验证据的支持：（1）首先也是最重要的是Rietveld对中子粉末衍射数据的分析，这表明在宽范围的不存在二次结晶相的情况下掺杂水平和（2）X射线光电子能谱，显示出2 p _3/2峰的独特形状，是Mn ^4+的特征。（6）此外，我们注意到实验Mg：Mn比之间的出色一致性通过元素分析确定，并根据理论公式计算得出Na ₄ Mg _{1-2 x} Mn ^IV _x（WO₄）₃。没有实验证据支持在Na ₄ Mg（WO ₄）₃晶格中存在Mn ²⁺。作者宣称没有竞争性的经济利益。本文引用了其他6个出版物。