Structural aspects of nonlinear optics — tetrahedral rotations

✍ Scribed by J.G. Bergman; G.R. Crane

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 409 KB
• Volume: 41
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(76)85264-5

✦ Synopsis

We report the fEst use of optical second harmonic generation (SHG> as a technique for directly determining the degree to which molecuIes (tetrahedrons of GeO 4 and SiO+) have rotated in a cry&l as a function of temperature.*The systems studied are: (1) ferroelectric pb5 GegOll, hbcre SHG results show that as the Curie point is approached the Ge04 tetrahedron rotates as a unit through 8"; (2) quartz, where SHG results monitor the 16' rotation of the SiOe tetrahedron as a function of temperature. The technique (SHG) appears to have great potential as a tool for studying the molecular &cha-__ nits of phase transitions.