Nuclear and electronic resonance approaches to magnetic and lattice fluctuations in the two-chain family of organic compounds (perylene)2[M(S

Interaction of magnetic field-dependent Peierls and spin-Peierls ground states in(Per)2[Pt(mnt)Green1, Brooks2, Kuhns3 et al. 2011Phys. Rev. BSelf Cite103100View full textAdd to dashboardCite

“…Conversely, the influence of the [P t(mnt) 2 ] spin chains on the field dependence of the CDW boundary determined from electrical transport is small, as previously discussed by Almeida and Henriques [19]. This implies that the onset of tetramerization in the perylene chains creates the environment that triggers the symmetry breaking and dimerization in the P t(mnt) 2 chains, which might otherwise remain paramagnetic to lower temperatures (typically T sp << Θ Curie−W eiss ∼ 20 K [10]). …”

“…In contrast, the 1 H signal, due to the distance ( ≥ 4.8Å) between the protons and Pt spins, survives the phase transition out of the SP-CDW phase. Comparison with previous complementary studies [10] of (P er) 2 [Au(mnt) 2 ] (S = 0) and (P er) 2 [P t(mnt) 2 ] (S = 1/2) shows that the behavior of the 1 H NMR data is primarily sensitive to the spin configurations and dynamics of the [P t(mnt) 2 ] chains. Hence the behavior of the 1 H spectra and relaxation rates give a clear indication of the SP phase boundary as the singlet ground state is broken.…”

“…This is in fact a general characteristic of related organic conductors in this class, where 4k F instabilities can lead to CO and SP ground states [3], driven by Coulomb interactions. Moreover, based on the linear scaling of 1/T 1 vs. T χ, Bourbonnais et al [10] show the spin degrees of freedom remain diffusive and weak until T SP −CDW , and hence it is hard to see how the SP dimerization can be a result of, for instance quantum spin dynamics alone. We note however that since EPR studies indicate an interaction between the itinerant and localized spins, an exchange interaction might be involved in the cooperative SP-CDW transition.…”

“…This observation suggests that the two chains are strongly coupled, even with the mismatch in q-vectors. In light of this, one [9] and two chain [10] one dimensional Kondo lattice models have been considered in treating the coupling of the itinerant electrons and localized spins associated with the onset of the T SP −CDW transition, but at present there is no complete theory that treats the two-chain (P er) 2 [P t(mnt) 2 ] case. In the work presented here, we will show that even at high magnetic fields this coupling persists, and that the initial tetramerization in the perylene chains may promote the stabilization of the SP dimerization and the resulting spin-singlet ground state.…”

Peierls and Spin-Peierls Instabilities in the Per₂[M(mnt)₂] Series of One-Dimensional Organic Conductors; Experimental Realization of a 1D Kondo Lattice for M = Pd, Ni and Pt

“…The finding of a TSP distinct from TP seems to be sustained by extrapolation to 0K of the magnetic phase diagram [37]. The establishment of a low temperature spin-singlet ground state on [Pt(mnt)2] chains is evident from 1 H NMR spectra and spin relaxation (1/T1) rates [38,39]. However NMR cannot probe the spatial extend of the SP order.…”