| Popis: |
We report on the application of femtosecond x-ray scattering to experimental studies of the photo-induced, structuralphase transition in V02. The transition between the two crystalline phases of the material occurs, for sufficientlyintense excitation, within 500 fs. 1. INTRODUCTION In recent years, significant efforts have been dedicated to the generation of femtosecond pulses of x-rays, to be usedfor dynamic structural measurements during phase transitions and chemical reactions. These experimental toolsallow for simultaneous access to the ultrashort timescale ( iO' 1012 sec) and to the Angstroem length-scale withsensitivity to atomic arrangement. In fact, while the femtosecond time domain has been accessible for more than twodecades using ultrashort laser pulses', the structural properties of matter are only indirectly accessible using these optical wavelengths. Visible light is only sensitive to the dynamics of the valence electrons, which carry littleinformation of the actual structural properties of matter. Inasmuch as hard x-rays couple with localized core |
