$\mathrm{Th}{\mathrm{Mn}}_{12}$ nitrides are good candidates for high performance permanent magnets. However, one of the remaining challenges is to transfer the good properties of the powder into a useful bulk magnet. Thus, understanding the denitrogenation process of this phase is of key importance. In this study, we investigate the magnetic and structural stability of the ${({\mathrm{Nd}}_{0.75},{\mathrm{Pr}}_{0.25})}_{1.2}{\mathrm{Fe}}_{10.5}{\mathrm{Mo}}_{1.5}{\mathrm{N}}_x$ compound ($x=0$ and 0.85) as function of temperature by means of neutron powder diffraction. Thermal dependence of the lattice parameters, formation of $\alpha$-(Fe,Mo), as well as the nitrogen content in the nitrides are investigated by heating the compounds up to 1010 K. The decomposition takes place mainly via the formation of the $\alpha$-(Fe,Mo) phase, which starts at around 900 K, whereas the nitrogen remains stable in the lattice. Additionally, we show that the magnetic properties of the nitrides [$M\left(4\text{T}\right)=90$ ${\mathrm{Am}}^2$/kg and $H_c=0.55$ T] are maintained after the thermal treatments up to 900 K. This study demonstrates that the $\mathrm{Th}{\mathrm{Mn}}_{12}$ nitrides with the Mo stabilizing element offer good prospects for a bulk magnet provided an adequate processing route is found.

中文翻译：

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原位中子粉末衍射法对ThMn12氮化物中的脱氮过程

$钍{锰}_{12}$氮化物是高性能永磁体的良好选择。然而，剩下的挑战之一是将粉末的良好性能转移到有用的块状磁体中。因此，了解该阶段的脱氮过程至关重要。在这项研究中，我们调查了${（{钕}_{0.75}，{镨}_{0.25}）}_{1.2}{铁}_{10.5}{莫}_{1.5}{\mathrm{ñ}}_X$ 复合（$X=0$通过中子粉末衍射得到的温度为0.85）。晶格参数的热依赖性，形成$\alpha$通过加热化合物至1010 K，研究了-（Fe，Mo）以及氮化物中的氮含量。分解主要是通过形成 $\alpha$-（Fe，Mo）相开始于900 K附近，而氮在晶格中保持稳定。此外，我们证明了氮化物的磁性[$\mathrm{中号}（4\text{Ť}）=90$ ${\mathrm{上午}}^2$/ kg和 $H_C=0.55$ T]在热处理后最高可保持900K。这项研究表明， $钍{锰}_{12}$ 如果找到了适当的加工路线，则具有Mo稳定元素的氮化物为块状磁体提供了良好的前景。