Second-order nonlinear optical and linear ultraviolet-visible absorption properties of the type-II multiferroic candidates RbFe(AO4)2 ( A=Mo,Se,S )
Second-order nonlinear optical and linear ultraviolet-visible absorption properties of the type-II multiferroic candidates RbFe(AO4)2 ( A=Mo,Se,S )
复制标题
II型多铁性候选材料RbFe(AO4)2 ( A=Mo,Se,S )的二阶非线性光学和线性紫外可见吸收特性
DOI：
10.1103/physrevb.103.054104
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发表时间：
2021
影响因子：
3.7
通讯作者：
Zhao, Liuyan
中科院分区：
文献类型：
--
作者：
Owen, Rachel;Drueke, Elizabeth;Albunio, Charlotte;Kaczmarek, Austin;Jin, Wencan;Obeysekera, Dimuthu;Cheong, Sang-Wook;Yang, Junjie;Cundiff, Steven;Zhao, Liuyan
受寻找II型多铁性的激励，我们提出了一种II型多铁性候选的复杂氧化物家族的全面的光学研究：、和。我们使用旋转各向异性二次谐波产生光谱(RA SHG)，这是一种对点对称性敏感的技术，以解决文献中指定的点/空间群中的差异并识别正确的晶体结构。在室温下，我们发现我们的RA倍频图案偏离()中的晶轴旋转，这表明缺乏镜像对称性和面内二重旋转对称性。此外，倍频效率比()大两个数量级，这表明反转对称性被破坏。此外，我们还利用紫外-可见吸收光谱在这类材料的带边附近给出了随温度变化的线性光学特性。其中包括这一族的带隙能量和带隙跃迁类型的实验证据。还给出了子带隙吸收，它显示了显著的光学跃迁，其中一些具有不寻常的中心能量温度依赖关系。此外，我们发现通过在()中替换Site，上述跃迁在光谱上是可调的。最后，我们讨论了这些可调跃迁的潜在来源和影响。
Motivated by the search for type-II multiferroics, we present a comprehensive optical study of a complex oxide family of type-II multiferroic candidates:, and. We employ rotational-anisotropy second harmonic generation spectroscopy (RA SHG), a technique sensitive to point symmetries, to address discrepancies in literature-assigned point/space groups and to identify the correct crystal structures. At room temperature we find that our RA SHG patterns rotate away from the crystal axes in(), which identifies the lack of mirror symmetry and in-plane two-fold rotational symmetry. Also, the SHG efficiency ofis two orders of magnitude stronger than(), which suggests broken inversion symmetry. Additionally, we present temperature-dependent linear optical characterizations near the band edge of this family of materials using ultraviolet-visible absorption spectroscopy. Included is experimental evidence of the band gap energy and band gap transition type for this family. Subband gap absorption is also presented, which reveals prominent optical transitions, some with an unusual central energy temperature dependence. Furthermore, we find that by substituting thesite in(), the aforementioned transitions are spectrally tunable. Finally, we discuss the potential origin and impact of these tunable transitions.