The Journal of Physical Chemistry C · 2017 · 20 citations · 34 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsSolid State PhysicsSpectroscopyElectron-phonon InteractionsNanoscale MaterialsPhase ChangePhase TransitionsPolymorphism AnalysisRaman SpectroscopyNormal ModesPhase Transition TemperaturePolymorph IdentificationRaman Data AnalysisRaman ScatteringRaman SpectraTemperature-dependent Raman SpectroscopyVibrational Mode Assignment
A Raman scattering investigation of a single α-CuPc nanorod is demonstrated here within the temperature range 300–770 K. From the typical thermal dispersion of Raman shift and phonon line width of in-plane B 1g mode at 1526 cm –1, the metastable α polymorph is observed to undergo unambiguous phase transition to thermally stable β phase. The phase transition temperature (456 K) is observed to be significantly lower than that reported for bulk samples. Extensive computation of normal modes associated with both α- and β-CuPc reveal that the “fingerprint” domain across 1300–1600 cm –1 is particularly sensitive to this polymorphic transition where a silent B 2g mode appears at 1303 cm –1 in the spectral vicinity of molecular edge vibration sensitive A g –B g Davydov doublet.
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Potential for spin-based information processing in a thin-film molecular semiconductor
Marc Warner, Salahud Din, I. S. Tupitsyn et al. · Nature · 2013 · 290 citations