scholarly journals First-Principles Calculations and Optical Absorption Spectrum of a Light-Colored Aluminum-Substituted ε-Iron Oxide Magnet

2017 ◽  
Vol 2017 (3) ◽  
pp. 530-530 ◽  
Author(s):  
Tomomichi Nasu ◽  
Marie Yoshikiyo ◽  
Hiroko Tokoro ◽  
Asuka Namai ◽  
Shin-ichi Ohkoshi
2011 ◽  
Vol 1370 ◽  
Author(s):  
Yufeng Liang ◽  
Li Yang

ABSTRACTA first-principles study on the quasiparticles energy and optical absorption spectrum of fluorographene is presented by employing the GW + Bethe-Salpeter Equation (BSE) method with many-electron effects included. The calculated band gap is increased from 3.0 eV to 7.3 eV by the GW approximation. Moreover, the optical absorption spectrum of fluorographene is dominated by enhanced excitonic effects. The prominent absorption peak is dictated by bright resonant excitons around 9.0 eV that exhibit a strong charge transfer character, shedding light on the exciton condensation and relevant optoelectronic applications. At the same time, the lowest-lying exciton at 3.8 eV with a binding energy of 3.5 eV is identified, which gives rise to explanation of the recent ultraviolet photoluminescence experiment.


1998 ◽  
Vol 76 (4) ◽  
pp. 411-413
Author(s):  
Yixing Zhao ◽  
Gordon R Freeman

The energy and asymmetry of the optical absorption spectrum of solvated electrons, es- , change in a nonlinear fashion on changing the solvent through the series HOH, CH3OH, CH3CH3OH, (CH3)2CHOH, (CH3)3COH. The ultimate, quantum-statistical mechanical, interpretation of solvated electron spectra is needed to describe the solvent dependence. The previously reported optical spectrum of es- in tert-butanol was somewhat inaccurate, due to a small amount of water in the alcohol and to limitations of the infrared light detector. The present note records the remeasured spectrum and its temperature dependence. The value of the energy at the absorption maximum (EAmax) is 155 zJ (0.97 eV) at 299 K and 112 zJ (0.70 eV) at 338 K; the corresponding values of G epsilon max (10-22 m2 aJ-1) are 1.06 and 0.74. These unusually large changes are attributed to the abnormally rapid decrease of dielectric permittivity of tert-butanol with increasing temperature. The band asymmetry at 299 K is Wb/Wr = 1.8.Key words: optical absorption spectrum, solvated electron, solvent effects, tert-butanol, temperature dependence.


2016 ◽  
Vol 109 (26) ◽  
pp. 263104 ◽  
Author(s):  
Baomin Wang ◽  
Xuewei Cao ◽  
Zhan Wang ◽  
Yong Wang ◽  
Kaihui Liu

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