Dimerization in α-TiCland α-TiBr: the DFT study.

A series of DFT calculations for two layered compounds with honeycomb lattice-α-TiCland α-TiBrhas been performed. It was shown that the symmetric SU(4) spin-orbital model recently proposed forsystems with honeycomb lattice cannot be realized in these titanates because they dimerize in the low temperature phase. This explains experimentally observed drop in magnetic susceptibility of α-TiBr.

Spectral and magnetic properties of NaRuO.

We present measurements of resistivity, x-ray absorption (XAS) and emission (XES) spectroscopy together with ab initio band structure calculations for quasi two dimensional ruthenate NaRuO. Density function calculations (DFT) and XAS and XES spectra both show that NaRuO is a semiconductor with an activation energy of  ∼80 meV. Our DFT calculations reveal large magneto-elastic coupling in NaRuO and predict that the ground state of NaRuO should be antiferromagnetic zig-zag.

Valence states and possible charge ordering in LaCo(1-x)Rh(x)O₃.

An unusual effect was discovered in Li et al (2010 J. Solid State Chem. 183 1388): the substitution of nonmagnetic low-spin Co(3+) in LaCoO3 by the formally isoelectronic and also nonmagnetic Rh(3+) led, surprisingly, to a rapid appearance of magnetism in LaCo(1-x)Rh(x)O3, even for small amounts of doping.