Double perovskites electronic structure

Phosphors are composed of a semiconductor host and an activator, and both the host and the activator absorb and transfer excitation energy to the excited state of the activator. Double-perovskite A2B(MoAV)Oe with a monoclinic or pseudo-cubic structure, are substantially absorbed in the NUV region [22]. The excitation spectra of the double-perovskite SraCaWOgiEu exhibit a broad absorption band to blue light in the NUV region. This phenomenon occurs because of the charge-transfer (CT) transitions of O to W in the WOg octahedral and the/-/electronic transitions of the Eu activators. 

Wu, H. (2001) Electronic structure study of double perovskites A2FeRe06 (A = Ba,... 

Tlie plienomenon of half-metallicity has gained much interest in order to understand the unusual band structures in various classes of materials and their potential applications in future electronic devices. For example, zinc blend pnictides and chalcogenides e.g. CrAs) are another class of non-oxide materials (apart from Heuslers) in addition to the many oxide classes that are potentially half-metallic materials. Alkali metal doped rare earth oxomanganates, (REi- A MnOs), rutile-Cr02, spinel-Fe304 and Sr2peMo06 double perovskite oxide are examples of important half-metallic oxides. 

Due to its metallic and FM property, similar to double perovskites (see later), Cr02 is of great interest to material scientists and physicists. A computed band structure of Cr02 is shown in Figure 5.6. The Fermi level crosses the majority-spin band while it lies in a gap of the minority-spin density of states (DOS). Therefore, Cr02 is half-metallic on the basis of electronic structure calculations. The same band structure has been reproduced by several groups since it was first demonstrated by... 

Electronic Structure and Magnetic Properties of Double Perovskites... 

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