相关论文: Multi-gap absorption in CaCu$_{3}$Ti$_{4}$O$_{12}$…

We studied the optical conductivity of electron doped Pr{1-x)Ce(x)CuO(4) from the underdoped to the overdoped regime. The observation of low to high frequency spectral weight transfer reveals the presence of a gap, except in the overdoped…

Halide perovskites constitute a chemically-diverse class of crystals with great promise as photovoltaic absorber materials, featuring band gaps between about 1 and 3.5 eV depending on composition. Their diversity calls for a general…

Using transmission electron microscopy (TEM) we studied CaCu3Ti4O12, an intriguing material that exhibits a huge dielectric response, up to kilohertz frequencies, over a wide range of temperature. Neither in single crystals, nor in…

We have studied the electronic and magnetic properties of the A- and B-site-ordered perovskite CaCu3Re2Fe2O12 within the density-functional theory using the generalized gradient approximation (GGA) with the consideration of strong Coulomb…

Density functional plus dynamical mean field calculations are used to show that in transition metal oxides, rotational and tilting (GdFeO$_3$-type) distortions of the ideal cubic perovskite structure produce a multiplicity of low-energy…

The effect of 14 organic cations on the optical properties of the lead iodine perovskite is analyzed. The electronic and optical properties are obtained using first principles. The absorption coefficients are split into inter-atomic species…

We investigate the electronic and magnetic structures and the character and direction of spin and orbital moments of the recently synthesized quadruple perovskite cobaltovanadate CaCo3V4O12 using a selection of methods from density…

We have systematically studied the strong correlation effects in A-site ordered perovskites CaCu3Ti4-xRuxO12 (x = 0, 1, 3.5, and 4) by using photoemission and inverse photoemission spectroscopies. In x = 0, 1, 3.5, the peak positions of the…

We study a selection of Cu-containing magnetic quadruple perovskites (CaCu$_{3}$Ti$_{4}$O$_{12}$, LaCu$_{3}$Fe$_{4}$O$_{12}$, and YCu$_{3}$Co$_{4}$O$_{12}$) by ab initio calculations, and show that Cu is in an effective divalent Cu(II)-like…

Using the full-potential linearized-augmented-plane-wave (FLAPW) method, we have analyzed systematically the trends in the structural and electronic properties of the 3d and 4d transition-metal oxides SrMO_3 (M = Ti, V, Zr and Nb). The…

We report angle-resolved photoemission spectroscopy (ARPES) results of A-site ordered perovskite CaCu$_3$Ti$_4$O$_{12}$. We have observed the clear band dispersions, which are shifted to the higher energy by 1.7 eV and show the band…

Two perovskite-derived materials, CaCu3Mn4O12 and CaCu3Ti4O12, have drawn much recent interest due to their magnetoresistive, dielectric, and magnetoelectronic characteristics. Here we present initial theoretical insights into each of these…

Band gap engineering in SrTiO${}_{3}$ and related titanate perovskites has long been explored due to the intriguing properties of the materials for photocatalysis and photovoltaic applications. A popular approach in the materials chemistry…

Quaternary chalcogenide crystal Cu2CdGeS4 was studied both experimentally and theoretically in the present paper. Investigations of polarized fundamental absorption spectra demonstrated a high sensitivity to external light illumination. The…

The transition--metal oxide CaCu$_3$Ru$_4$O$_{12}$ with perovskite--type structure shows characteristic properties of an intermediate--valence system. The temperature--dependent susceptibility exhibits a broad maximum around $150 - 160$ K.…

The cubic perovskite-related ceramic CaCu3Ti4O12 has a very high static dielectric constant ~10000 at room temperature (RT), which drops to about 100 below about 100 K. Substituting Cd for Ca reduces the RT value of the dielectric constant…

Electronic structures of the filled-skutterudite compounds PrRu$_4$P$_{12}$ and SmRu$_4$P$_{12}$, which undergo a metal-insulator transition (MIT) at $T_{\rm MI}$ = 60 K and 16 K, respectively, have been studied by means of optical…

Recently, it was experimentally shown that the performance and thermal stability of the perovskite MAPbI$_3$ were improved upon the adsorption of a molecular layer of caffeine. In this work, we used a hybrid methodology that combines…

Stability and toxicity issues with the hybrid lead iodide perovskite MAPbI$_3$ necessitate a hunt for potential alternatives. Here, we shed light on promising photovoltaic properties of gold mixed-valence halide perovskites…

CaCu$_3$Fe$_4$O$_{12}$ exhibits a temperature-induced transition from a ferrimagnetic-insulating phase, in which Fe appears charge disproportionated, as Fe$^{3+}$ and Fe$^{5+}$, to a paramagnetic-metallic phase at temperatures above 210 K,…