V. Hardy

Valence, spin, and orbital state of Co ions in one-dimensional Ca3Co2O6 : An x-ray absorption and magnetic circular dichroism study

We have investigated the valence, spin, and orbital state of the Co ions in the one-dimensional cobaltate Ca3Co2O6 using x-ray absorption and x-ray magnetic circular dichroism at the Co-L2,3 edges. The Co ions at both the octahedral Cooct and trigonal Cotrig sites are found to be in a 3+ state. From the analysis of the dichroism we established a low-spin state for the Cooct and a high-spin state with an anomalously large orbital moment of 1.7B at the Co trig ions. This large orbital moment along the c-axis chain and the unusually large magnetocrystalline anisotropy can be traced back to the double occupancy of the d2 orbital in trigonal crystal field.

Strongly correlated properties of the thermoelectric cobalt oxide Ca3Co4O9

We have performed both in-plane resistivity, Hall effect, and specific heat measurements on the thermoelectric cobalt oxide

Revisiting some chalcogenides for thermoelectricity

{\mathrm{Ca}}_{3}{\mathrm{Co}}_{4}{\mathrm{O}}_{9}

Quantum tunneling of the magnetization in the Ising chain compound Ca3Co2O6

. Four distinct transport regimes are found as a function of temperature, corresponding to a low temperature insulating one up to

Scaling behavior in thermoelectric misfit cobalt oxides.

{T}_{\mathit{min}}\ensuremath{\approx}63\phantom{\rule{0.3em}{0ex}}\mathrm{K}

Staircase effect in metamagnetic transitions of charge and orbitally ordered manganites

, a strongly correlated Fermi liquid up to

Specific heat and magnetization study on single crystals of the frustrated quasi-one-dimensional oxideCa3Co2O6

{T}^{*}\ensuremath{\approx}140\phantom{\rule{0.3em}{0ex}}\mathrm{K}

The fishtail effect in different Tl based single crystals. A possible interplay with the electronic anisotropy

, with

Columnar defects induced by high energy heavy ions in HTSC. Their effect on irreversibility line and pinning properties

\ensuremath{\rho}={\ensuremath{\rho}}_{0}+A{T}^{2}

Magnetocaloric effect and improved relative cooling power in (La0.7Sr0.3MnO3/SrRuO3) superlattices

and