论文标题
K富含磁性的Cryptomelane，K $ _x $ _MN $ _8 $ o $ $ _ {16} $（$ x \ of1.46 $）
Incommensurate magnetic modulation in K-rich cryptomelane, K$_x$Mn$_8$O$_{16}$ ($x\approx1.46$)
论文作者
论文摘要
Cryptomelane是一种类似荷兰石的材料，由$α$ -MNO $ _2 $ tim-tim tunnel样晶体图主题组成的K $^+$ cations。具有化学计量的样本K $ _ {1.461（4）} $ Mn $ _8 $ o $ $ _ {16} $已合成，并使用可变温度的磁性敏感性，热容量和中子粉末衍射进行了研究的磁性属性。 $ 184 $ \，k，$ 54.5 $ \，k和$ 24 $ \，k分配给k $ _ {1.461（4）} $ mn $ _8 $ o $ $ $ $ _ {16} $。磁性bragg峰出现在$ 54.5 $ \，K及其位置以下，它们表明与晶体学核结构不相关的调制磁性结构。与数据一致的模型是双 - $ \ vec {k} _ \ mathrm {magrm {mag} $结构，带有倾斜的ferrimagnetic $ \ vec {k} _ \ mathrm {magrm {magrm {magrm {magrm {mag} = 0 $ component and component and component and incommentarate $ \ vec {k} $ \ vec {k} $ kag _ \ mathrmmmatrmmmmmmmmmmmmmmmm {0 [$ k_z = 0.36902（15）$]组件，后者最有可能是针对该材料提出的螺旋类型。低于24 \，k，有一个磁过渡，这会导致一组不同的磁性布拉格峰，指示高度复杂的磁性结构。
Cryptomelane is a hollandite-like material consisting of K$^+$ cations in an $α$-MnO$_2$ tunnel-like crystallographic motif. A sample with stoichiometry K$_{1.461(4)}$Mn$_8$O$_{16}$ has been synthesised and its magnetic properties investigated using variable-temperature magnetic susceptibility, heat capacity, and neutron powder diffraction. Three distinct magnetic transitions at $184$\,K, $54.5$\,K, and $24$\,K are assigned to K$_{1.461(4)}$Mn$_8$O$_{16}$. Magnetic Bragg peaks emerge below $54.5$\,K, and from their positions they indicate a modulated magnetic structure which is incommensurate with the crystallographic nuclear structure. The model consistent with the data is a dual-$\vec{k}_\mathrm{mag}$ structure with a canted ferrimagnetic $\vec{k}_\mathrm{mag}=0$ component and an incommensurate $\vec{k}_\mathrm{mag}=(0,0,k_z)$ [$k_z=0.36902(15)$] component, with the latter most likely to be of the helical type formerly proposed for this material. Below 24\,K, there is a magnetic transition, which gives rise to a different set of magnetic Bragg peaks indicative of a highly complex magnetic structure.
