Structural, electronic, and magnetic properties of a crystalline material formed by parallel chains of silver atoms inside the tunnels of a manganese dioxide host with the hollandite structure, ${\mathrm{Ag}}_x{\mathrm{Mn}}_8{\mathrm{O}}_{16}$, are studied with density functional theory (DFT) calculations. More magnetic structures were studied, including ferromagnetic (FM) and C2 antiferromagnetic (C2-AFM) orderings on Mn atoms of pristine hollandite ${\mathrm{Mn}}_8{\mathrm{O}}_{16}$ and the FM state of ${\mathrm{Ag}}_x{\mathrm{Mn}}_8{\mathrm{O}}_{16}$. Thereby, Hubbard corrections and different values for the Ag content, $x\le 2$, were considered. The results show that hollandite ${\mathrm{Mn}}_8{\mathrm{O}}_{16}$ is a semiconducting oxide both in the FM and in the AFM states, but with the C2-AFM configuration as the ground state. Interestingly, for the FM state of ${\mathrm{Ag}}_x{\mathrm{Mn}}_8{\mathrm{O}}_{16}$ for high silver content, $x=2$, the system is a perfect and isotropic half-metal, but when not all tunnels are filled with Ag chains, i.e., for $x<2$, it behaves as a quasi-one-dimensional system retaining the perfect half-metallicity. The results demonstrate that the incorporation of the monoatomic Ag chains inside the hollandite ${\mathrm{Mn}}_8{\mathrm{O}}_{16}$ host leads to a stable system that can be used as a spin filter for instance for spintronics devices.

中文翻译：

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Silver hollandite (AgxMn8O16,x≤2)：用于自旋电子学的高度各向异性的半金属

晶体材料的结构、电子和磁性特性，由具有荷兰石结构的二氧化锰主体隧道内的平行银原子链形成， ${银}_X{锰}_8{\mathrm{哦}}_{16}$, 用密度泛函理论 (DFT) 计算进行研究。研究了更多的磁性结构，包括原始荷兰石锰原子上的铁磁 (FM) 和 C2 反铁磁 (C2-AFM) 排序${锰}_8{\mathrm{哦}}_{16}$ 和 FM 状态 ${银}_X{锰}_8{\mathrm{哦}}_{16}$. 因此，哈伯德修正和不同的银含量值，$X\le 2$， 被认为是。结果表明，荷兰石${锰}_8{\mathrm{哦}}_{16}$是 FM 和 AFM 状态的半导体氧化物，但具有 C2-AFM 配置作为基态。有趣的是，对于 FM 状态${银}_X{锰}_8{\mathrm{哦}}_{16}$ 含银量高， $X=2$，该系统是一个完美的各向同性的半金属，但当并非所有隧道都充满 Ag 链时，即对于 $X<2$，它表现为一个准一维系统，保留了完美的半金属性。结果表明，单原子银链在荷兰石内部的结合${锰}_8{\mathrm{哦}}_{16}$ 主机导致一个稳定的系统，可以用作自旋过滤器，例如自旋电子器件。