Mode anharmonicity in molecular crystals studied by piezomodulated Raman spectrosocpy

White, Kenneth M.; Eckhardt, Craig J.

doi:10.1103/physrevlett.59.574

Cited by 12 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resulting 28 cm Ϫ1 mode in the gamma phase has also been shown to exhibit a large PR response. 10 The research demonstrates that piezomodulated Raman spectroscopy can be used for direct measurement of the anisotropy of the anharmonicity of both inter-and intramolecular vibrational modes. This information, which is rarely determined and then only with difficulty, offers the potential for significant new experimental and theoretical insights into the vibrational behavior of molecules and crystals.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Anisotropic anharmonicity of lattice and molecular vibrations of 1,2,4,5-tetrabromobenzene determined by piezomodulated Raman spectroscopy

White

Eckhardt

1995

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

Strain-induced coupling constants for the anharmonicity of Raman-active lattice and certain molecular modes of vibration in 1,2,4,5-tetrabromobenzene ͑TBB͒ crystals have been determined using piezomodulated Raman spectroscopy. These constants, which are directly related to the first anharmonic term in the potential energy expansion for lattice dynamical calculations, are a quantitative measurement of the modal anharmonicities in the TBB molecular crystal. Application of uniaxial stress in the experiments permits the anisotropy of the anharmonicity to be determined as well as its magnitude. The TBB lattice modes are significantly coupled by the induced strains and the effects of coupling were observed to be dependent on the direction and symmetry of the strains. The molecular modes investigated were, by comparison, less coupled by the acoustic phonons and generally exhibited less anharmonic response with increasing frequency.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Instrumentation used to analyze and detect the scattered light is described elsewhere. 10,19 IV. RESULTS…”

Section: Methodsmentioning

confidence: 99%

Anisotropic anharmonicity of lattice and molecular vibrations of 1,2,4,5-tetrabromobenzene determined by piezomodulated Raman spectroscopy

White

Eckhardt

1995

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Since the stress applied to the crystal is relatively small, only changing the energy by about l%, 25 where 7f0 is the Hamiltonian of the undeformed lattice. The Hamiltonian of the perturbed lattice, 7ff, can be renormalized after the normal coordinates Q(0J) are separated into two parts,…”

Section: Afl(n)mentioning

confidence: 99%

Energetics of Organic Solid-State Reactions: Piezomodulated Raman Spectroscopy, Modal Motion, and Anharmonicity in the 2,5-Distyrylpyrazine (DSP) Photoreaction

Peachey¹,

Eckhardt²

1994

J. Phys. Chem.

Self Cite

View full text Add to dashboard Cite

The concepts of phonon assistance and chemical pressure have been advanced to better understand the collective nature of the energetics and dynamics of solid-state reactions. With the 2,5-distyrylpyrazine photoreaction, these hypotheses were examined by employing lattice dynamical calculations and Raman and piezomodulated Raman spectroscopy in the lattice mode region. Since modal motion and anharmonicity are important in substantiating these models, the analysis of this solid-state reaction focused on these aspects. The motions calculated by lattice dynamical methods are consistent with the results from the piezomodulated Raman spectra.The anharmonicity of the phonon modes was found to increase significantly following the initiation of the reaction. This was particularly evident for those modes having motions along the reaction coordinate. Chemical pressure is shown to be of great utility in explaining this solid-state reaction while phonon-phonon interactions are demonstrated to have no significant role.

show abstract

Cold tests of open coaxial resonators in the range 9–17 GHz

Castro

Barroso

Correa

1993

Int J Infrared Milli Waves

View full text Add to dashboard Cite

A study of selective properties of coaxial open cylindrical resonators have been conducted experimentally and compared with theory. The resonator consists of an inner circular cylinder symmetrically located inside an outer weakly irregular open waveguide. Several fundamental TE modes were identified over the range 9 to 17 CHz through measurements of the resonant frequencies and the associated loaded quality factors. It has been verified that the structure and the number of resonant modes are both strongly dependent on the diameter of the coaxial insert. Such an electrodynamical system proves to be useful in guided wave applications requiring, for example, filters, frequencytunable resonators and devices for analyzing the modal composition of a signal.

show abstract

Mode anharmonicity in molecular crystals studied by piezomodulated Raman spectrosocpy

Cited by 12 publications

References 11 publications

Anisotropic anharmonicity of lattice and molecular vibrations of 1,2,4,5-tetrabromobenzene determined by piezomodulated Raman spectroscopy

Anisotropic anharmonicity of lattice and molecular vibrations of 1,2,4,5-tetrabromobenzene determined by piezomodulated Raman spectroscopy

Energetics of Organic Solid-State Reactions: Piezomodulated Raman Spectroscopy, Modal Motion, and Anharmonicity in the 2,5-Distyrylpyrazine (DSP) Photoreaction

Cold tests of open coaxial resonators in the range 9–17 GHz

Contact Info

Product

Resources

About