Abstract
Polarized specular reflectance measurements over the energy range 0.6-5 eV are reported for two crystalline forms of tetrathiafulvalenium iodide (TTF-In). Since the plane of each TTF molecule is either approximately parallel or perpendicular to an external face of each crystal, polarized reflectance measurements can sample the various symmetry-allowed electronic transitions of the TTF molecule. The optical constants have been determined by means of a Lorentzian oscillator fit. A Drude-like edge is seen for light polarized along the conducting axis of monoclinic TTF-In (n∼0.7). Structure in the reflectance data for light polarized perpendicular to the stacking axes in both forms of TTF-In is interpreted as being primarily due to in-plane transitions of the TTF+ ion. Transitions polarized along the long and short axes of the TTF+ ion in orthorhombic TTF-In (n=2) can be resolved to aid in the assignment of the transitions for the TTF+ ion.
Original language | English |
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Pages (from-to) | 3238-3241 |
Number of pages | 4 |
Journal | Physical Review B |
Volume | 14 |
Issue number | 8 |
DOIs | |
State | Published - 1976 |
Externally published | Yes |