Charge-density-wave dynamics in the molecular conductor (perylene ) 2 Pt(mnt ) 2 (mnt=…

1995; American Physical Society; Volume: 52; Issue: 4 Linguagem: Inglês

10.1103/physrevb.52.r2237

ISSN

1095-3795

Autores

Elsa B. Lopes, Manuel Matos, R.T. Henriques, Manuel Almeida, J. Dumas,

Tópico(s)

Magnetism in coordination complexes

Resumo

We report the observation of nonlinear voltage response both to dc current and to unipolar current pulses in the commensurate charge-density-wave (CDW) state of the molecular conductor (perylene${)}_{2}$Pt(mnt${)}_{2}$ (mnt=maleonitriledithiolate). At T=4.2 K, two nonlinearities in the I-V curves are observed at ${\mathit{E}}_{\mathit{t}1}$=8.9 V ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ and ${\mathit{E}}_{\mathit{t}2}$\ensuremath{\sim}30 V ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. Above the threshold field ${\mathit{E}}_{\mathit{t}1}$, quasiperiodic asymmetric voltage spikes with large amplitude superimposed on the transient voltage response have been observed. The onset of the spikes shows a delay with respect to the leading edge of the pulse. The Fourier analysis of the voltage at constant current reveals one fundamental frequency, proportional to the CDW current density, accompanied by a large number of harmonics. The results are discussed in relation to the current models for CDW nonlinear transport.

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