Two-dimensional measurements of soft phonons and phase transitions in SrTiO3

✍ Scribed by D. Hohlwein; H.M. Mayer; H.-B. Neumann

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 206 KB
• Volume: 213-214
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(95)00342-7

✦ Synopsis

The flat-cone instrument at the BER-11 reactor in Berlin is well suited for systematic measurements of elastic and inelastic scattering events in large and continuous areas of Q-space. With this instrument the soft phonon branch, connected with the structural phase transition in SrTiO3, has been studied in the (hll) plane. In integral measurements the phonon branch shows up as two triangular intensity distributions around the superlattice points. The two-dimensional intensity distributions for a constant energy transfer reveal the anisotropy of the branch. The data collection time is considerably faster than with a conventional triple-axis instrument.