Charge density wave transition and instability in interchain coupled organic ferromagnets with next-nearest-neighbor hopping interaction

Abstract

Articles you may be interested inTemperature dependent reflectivity and anisotropic magnetization reversal in magnetically doped quasi-twodimensional charge density wave alloys A 0.01 Nb Se 2 ( A = Cr , Mn , Fe ) J. Appl. Phys. 103, 07D306 (2008); 10.1063/1.2856509 Density-functional study of intramolecular ferromagnetic interaction through m-phenylene coupling unit (II): Examination of functional dependence Effect of Fe cap layers on the spin density waves in epitaxial Cr(001) filmsConsidering interchain interaction and the intrachain next-nearest-neighbor hopping interaction, within the self-consistent-field Hartree-Fock approximation, we deal with two neighboring organic ferromagnetic chains. We take into account the -electrons, the Hubbard repulsion, and antiferromagnetic correlation between -electrons and side radical electrons. It is shown that there appear to be two kinds of charge density waves successively when the next-nearest-neighbor hopping interaction is greater than a critical value, which decreases with the interchain coupling. The first charge density wave is accompanied by a bond order wave and the second one has no lattice distortion. The spin density wave along the main chain is modulated by the charge density wave. It is also found that the interchain coupling and the next-nearest-neighbor hopping integral destabilizes the ferromagnetic ground states.

Quasi-one-dimensional Heisenberg antiferromagnetic model for an organic polymeric chain

“…We find that even for small U , the phases predicted by two models have some similarity. Comparing the present results with those in [12], one finds that the SP phase and the AF phase in this paper correspond to the incommensurate phase and commensurate phase in [12]. In the Peierlsextended Hubbard model in [12], both the NNN hopping terms along the chain and between the chain and the radical site are considered.…”

“…Comparing the present results with those in [12], one finds that the SP phase and the AF phase in this paper correspond to the incommensurate phase and commensurate phase in [12]. In the Peierlsextended Hubbard model in [12], both the NNN hopping terms along the chain and between the chain and the radical site are considered. The results by the ED and the CPMC techniques also show that when the NNN hopping increases the ground state transits from the high-spin state to the low-spin state.…”

“…It is interesting to compare the present results with those from the itinerant models. In the Hubbard-Kondo model for this polymer [12], the HFA result shows that as the NNN hopping increases to a critical value ρ c1 , the ferromagnetic ground state with high spin is unstable while there appears a phase with incommensurate CDW and SDW along the chain. As the NNN hopping increases continuously to another critical value ρ c2 , the ground state exhibits a commensurate CDW and SDW with a period of two sites.…”

“…ferrimagnetic long-range ordering. However, if the next-nearest-neighbour (NNN) hopping is considered, the ferrimagnetic ground state with high spin is unstable [12]. The HFA result shows that there appear to be two kinds of charge density wave (CDW) and spin density wave (SDW) successively when the NNN hopping increases.…”

Strong Ferromagnetic Coupling of {[Cu(Hpht)(N 3 )]·H 2 O} n with Simultaneous End-on Azido and Carboxylato Bridges: a First Principle Study

“…A number of azide-bridged copper (II) chain compounds, involving just 1,1-azides and combinations of 1, 1-azides and other bridges, have been structurally determined from experimental data [2,5] and studied by means of theoretical calculation on model compounds, [6] whereas there were few theoretical studies based on molecular entities for this system. In order to understand the magnetic and electronic properties of this series of compounds well, similar to our previous work on the pure organic magnets, [7,10] in the present paper, we report our accurate first-principles calculations on the actual compound {[Cu(Hpht)(N 3 )]•H 2 O} n , one of the azide-bridged copper (II) chain compounds. To our knowledge, this is the first attempt based on molecular entity for this compound.…”