M. D. Nunez-Regueiro

Interlayer magnetic frustration in quasistoichiometric Li1-xNi1+xO2

Susceptibility, high-field magnetization, and submillimeter-wave electron spin resonance measurements of layered quasistoichiometric Li 1 - x Ni 1 + x O 2 are reported and compared to isomorphic NaNiO 2 . A mechanism of magnetic frustration induced by the excess Ni ions always present in the Li layers is proposed. We finally comment on the possible realization of an orbital liquid state in this controversial compound.

Underscreened Kondo lattice model applied to heavy fermion uranium compounds

We present theoretical results for the underscreened Kondo lattice model with localized

Theory of the Kondo lattice : competition between Kondo effect and magnetic order

S=1

Coexistence of ferromagnetism and Kondo effect in the underscreened Kondo lattice

spins coupled to a conduction band through a Kondo coupling,

Valence bond state in the delafossite YCuO2.5

{J}_{K}

First-principles determination of exchange interactions in delafossite Y Cu O 2.5

, and interacting among them ferromagnetically. We use a fermionic representation for the spin operators and expand the Hamiltonian in terms of bosonic fields. For large values of

Structural phase transitions in CaSi2 under high pressure

{J}_{K}

Superconducting high pressure CaSi2 phase with Tc up to 14 K

, we obtain a ferromagnetically ordered solution and a Kondo regime with a Kondo temperature,

Decoupling of orbital and spin degrees of freedom in Li1 xNaxNiO2

{T}_{K}

The underscreened Kondo lattice model: application to uranium compounds

, larger than the Curie temperature,