6533b826fe1ef96bd1284ed9

RESEARCH PRODUCT

Simulataneous application of charge coupled device array-detected Raman spectroscopy and differential scanning calorimetry to in situ investigation of phase transitions in condensed matter

Jussi ValkonenUpali A. JayasooriyaMauno E. E. HarjuDaniel Wolverson

subject

Phase transitionAmmonium nitrateAnalytical chemistryCrystal structureIonchemistry.chemical_compoundsymbols.namesakeDifferential scanning calorimetrychemistrysymbolsCharge-coupled deviceCoherent anti-Stokes Raman spectroscopyPhysical and Theoretical ChemistryRaman spectroscopyPhysics::Atmospheric and Oceanic Physics

description

The combination of differential scanning calorimetry (DSC) with charge coupled device (CCD) array-detected Raman spectroscopy for the in situ investigation of phase transition is illustrated using ammonium nitrate as an example. This method aids unambiguous characterization of different phases by providing a simultaneous probe of thermodynamic and vibrational data. The availability of real-time vibrational data, including both the internal and external mode regions, is unique to array-detected Raman spectroscopy. The intensity changes of the symmetric stretching mode ν1 of the nitrate ions and the lattice vibrations, that accompany the phase transition IV → II of ammonium nitrate, are rationalized in terms of the known crystal structure data.

https://doi.org/10.1039/ft9928802717