Electronic excitations and optical properties of YbFe2O4 thin films
Electronic excitations and optical properties of YbFe2O4 thin films
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DOI：
10.1016/j.tsf.2019.01.035
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发表时间：
2019-03-01
期刊：
影响因子：
2.1
通讯作者：
Zeng, H.
中科院分区：
文献类型：
--
作者：
Rai, R. C.;Hinz, J.;Zeng, H.
本文报道了在（0001）蓝宝石衬底上沉积的YbFe 2 O 4薄膜的结构、光学性质和电子激发光谱。的YbFe 2 O 4薄膜的光谱显示几个电子跃迁，占主导地位的Fe d到d的电子跃迁，以及O 2 p到Fe 3d，Yb 6s，和Yb 5d的电荷转移电子跃迁。在300 K时，YbFe_2 O_4的直接能带隙为1.40 +/- 0.01 eV。此外，中心在1.75 eV和2.41 eV的电子跃迁表现出很强的温度依赖性，在类似于190 +/- 10 K的不连续性，表明系统中的结构不稳定性的证据。分析了YbFe_2 O_4的光谱，并与同构YbFe_2 O_4和LuFe_2 O_4的光谱进行了比较。
We present the structural, optical properties, and electronic excitation spectra of the YbFe2O4 thin film deposited on (0001) sapphire substrates. The optical spectra of a YbFe2O4 thin film show several electronic transitions, dominated by Fe d to d on-site electronic transitions as well as O 2p to Fe 3d, Yb 6s, and Yb 5d charge-transfer electronic transitions. The direct energy band gap of YbFe2O4 has been found to be 1.40 +/- 0.01 eV at 300 K. Moreover, the electronic transitions centered at 1.75 eV and 2.41 eV exhibit strong temperature dependence with a discontinuity at similar to 190 +/- 10 K, indicating evidence for a structural instability in the system. The optical spectra of YbFe2O4 have been analyzed and also compared with that of isostructural YbFe2O4 and LuFe2O4.