In this work, recent theoretical investigations by the authors in the area of oxide multilayers are briefly reviewed. The calculations were carried out using model Hamiltonians and a variety of non-perturbative techniques. Moreover, new results are also included here. They correspond to the generation of a metallic state by mixing insulators in a multilayer geometry, using the Hubbard and doubl...

We present experimental photoemission and inverse photoemission spectra of SrTiO3−δ representing electron doped d 0 systems. Photoemission spectra in presence of electron doping exhibit prominent features arising from electron correlation effects, while the inverse photoemssion spectra are dominated by spectral features explainable within single-particle approaches. We show that such a spectral...

Minerals are crystalline solids, and their properties are governed by quantum mechanics. Density functional theory in the local density approximation or the generalized gradient approximation gives accurate predictions for energetic properties of closed shell systems, as well as ionic/covalent crystals, and open-shelled transition metals and transition metals oxides. The electronic structure an...

Biodiesel production is worthy of continued study and optimization of production procedures due to its environmentally beneficial attributes and its renewable nature. Heterogeneous transesterification is considered to be a green process. The process requires neither catalyst recovery nor aqueous treatment steps and very high yields of methyl esters can be obtained, close to the theoretical valu...

G. Lucovsky 1, 2, , J. G. Hong, C. C. Fulton, Y. Zou, R. J. Nemanich, H. Ade, D. G. Scholm, and J. L. Freeouf 5 1 Department of Physics, North Carolina State University, USA 2 Department of Materials Science & Engineering, North Carolina State University, USA 3 Department of Electrical & Computer Engineering, North Carolina State University, USA 4 Department of Materials Science & Engineering, ...

We develop a general procedure to analyse the pre-edges in 1s x-ray absorption near edge structure (XANES) of transition metal oxides and coordination complexes. Transition metal coordination complexes can be described from a local model with one metal ion. The 1s 3d quadrupole transitions are calculated with the charge-transfer multiplet program. Tetrahedral coordination complexes have more in...

http://dx.doi.org/10.1016/j.orgel.2014.01.011 1566-1199/ 2014 Elsevier B.V. All rights reserved. ⇑ Corresponding authors at: Luminous! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore. E-mail addresses: [email protected] (H.V. Demir), exwsun@ntu....

Promising candidates for the next-generation memory devices have emerged one after another for the last decade. Ferroelectric random access memories (FeRAM), magnetoresistive random access memories (MRAM), phase change memories (PCM) are indeed at the dawn of the international development races. Along with those three fascinating memories, we focus here on probably the most seminal candidate of...

We present the main features of the spin-orbital superexchange which describes the magnetic and optical properties of Mott insulators with orbital degrees of freedom. In contrast to the SU(2) symmetry of spin superexchange, the orbital part of the superexchange obeys the lower cubic symmetry of the lattice and is intrinsically frustrated. This intrinsic frustration and spin-orbital entanglement...

The discovery by Tsuyoshi Kimura and colleagues of a multiferroic coupling in cupric oxide up to 230 K, as reported on page 291 of this issue1, is all the more remarkable as physicists had been wondering for a long time if it is possible at all to align electric dipoles by magnetic fields or change the direction of magnetization by applying voltage. To some, such a magnetoelectric coupling may ...