论文标题
α-banao4中的分子氧诱导的铁磁性和半金属性：第一原理研究
Molecule Oxygen Induced Ferromagnetism and Half-metallicity in α-BaNaO4: A First Principles Study
论文作者
论文摘要
分子氧类似于在化合物中表现出远距离自旋顺序和电子强相关行为的3D和4F金属。但是，铁磁旋转顺序和半金属性非常难以捉摸，并且没有得到很好的公认。在本文中，我们解决了这个问题，以研究旋转将如何相互相互作用，如果氧二聚体与已知的超级和每氧化物中通过第一原理计算以不同的方式排列。基于结构搜索，热力学研究和晶格动力学的结果，我们表明四方α-banao4是稳定的半属金属，在120 K时温度是Curie温度，这是这类化合物的第一个例子。像3D和4F金属一样，由于其π*轨道中的未配对电子，O2二聚体携带0.5μb的局部磁矩。该化合物可以被视为从堆叠到头部堆叠的O2二聚体层形成。与AO2（a = k，rb，cs）中的不同之处，旋转都在层内和层之间耦合。自旋极化发生在π*轨道中，具有完全占据价带的自旋电子，部分占据了传导带，分别形成了半导体和金属通道。我们的结果突出了O2二聚体在含有化合物的O2二聚体中的其他新型特性中的几何布置的IMSTARICTANES。
Molecule oxygen resembles 3d and 4f metals in exhibiting long-range spin ordering and electron strong correlated behaviors in compounds. The ferromagnetic spin ordering and half-metallicity, however, are quite elusive and have not been well acknowl-edged. In this article, we address this issue to study how spins will interact each other if the oxygen dimers are arranged in a dif-ferent way from that in the known super- and per-oxides by first principles calculations. Based on the results of structure search, thermodynamic study and lattice dynamics, we show that tetragonal α-BaNaO4 is a stable half-metal with a Curie temperature at 120 K, a first example in this class of compounds. Like 3d and 4f metals, the O2 dimer carries a local magnetic moment 0.5 μB due to the unpaired electrons in its π* orbitals. This compound can be regarded as forming from the O2 dimer layers stacking in a head to head way. Different from that in AO2 (A=K, Rb, Cs), the spins are both ferromagnetically coupled within and between the layers. Spin polarization occurs in π* orbitals with spin-up electrons fully occupying the valence band and spin-down electrons partially the conduction band, forming the semiconducting and metallic channels, respectively. Our results highlight the im-portance of geometric arrangement of O2 dimers in inducing ferromagnetism and other novel properties in O2 dimer containing compounds.
