Elastic, phononic, magnetic and electronic properties of quasi-one-dimensional PbFeBO4
Elastic, phononic, magnetic and electronic properties of quasi-one-dimensional PbFeBO4
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DOI：
10.1007/s10853-019-03866-1
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发表时间：
2019-11
影响因子：
4.5
通讯作者：
M. Curti;M. Curti;M. Murshed;T. Bredow;D. Bahnemann;D. Bahnemann;T. Gesing;C. Mendive
中科院分区：
文献类型：
--
作者：
M. Curti;M. Curti;M. Murshed;T. Bredow;D. Bahnemann;D. Bahnemann;T. Gesing;C. Mendive
莫来石型PbFeBO 4的多样性和有趣的特性导致了越来越多的出版物，使用实验和计算方法。然而，仍有几个问题有待探讨，如在微观水平上的内禀势非谐性的磁配置的作用，并在弹性性质和相关的压力引起的反应的核结构。因此，我们采用混合方法PW 1 PW研究的结构，声子，磁性和电子性质的PbFeBO 4在四个不同的磁性配置。磁性构型驱动的强各向异性的性质相关的两个结构特征，即，一维链的FeO 6八面体和立体化学活性的孤电子对的Pb 2+阳离子。我们提出了一个机制来解释观察到的轴向负线性压缩性在b方向。的振动特性表明洞察到的非谐行为的结构，和一个负模式Grüneisen参数的模式的大部分。通过优化四种不同的磁位形在不同的压力下的相关自旋交换参数的计算，磁位形显着影响的磁弹性行为的结构。通过GW 0-BSE计算的光吸收光谱显示出很强的各向异性，与准一维特征的结构给出的FeO 6链。
The diverse and interesting properties of mullite-type PbFeBO4have resulted in a growing number of publications, using both experimental and computational methodologies. However, several questions remain to be explored such as the role of the magnetic configuration on the intrinsic potential anharmonicity at a microscopic level, and on the elastic properties and associated pressure-induced response of the nuclear structure. We thus employ the hybrid method PW1PW to study the structural, phononic, magnetic and electronic properties of PbFeBO4at four different magnetic configurations. The magnetic configuration-driven strong anisotropy of the properties is correlated to two structural features, namely, the one-dimensional chains of FeO6octahedra and the stereochemical activity of the lone electron pairs of Pb2+cations. We propose a mechanism to explain the observed axial negative linear compressibility in thebdirection. The vibrational features demonstrate insights into the anharmonic behavior of the structure, and a large fraction of modes with negative mode Grüneisen parameters. By optimizing four different magnetic configurations at different pressures the associated spin exchange parameters are calculated; the magnetic configuration considerably affects the magneto-elastic behavior of the structure. Optical absorption spectra calculated by GW0-BSE show a strong anisotropy, associated with the quasi-one-dimensional character of the structure given by the FeO6chains.