High Pressure Raman Study of Lu3Al5O12

✍ Scribed by K. Papagelis; J. Arvanitidis; G. Kanellis; G. A. Kourouklis; S. Ves

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 185 KB
• Volume: 211
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/(sici)1521-3951(199901)211:1<301::aid-pssb301>3.0.co;2-r

✦ Synopsis

In the present paper we study the effect of high hydrostatic pressure (up to 16 GPa) on the Raman spectrum of Lu 3 Al 5 O 12 single crystals. Lu 3 Al 5 O 12 belongs to the crystal family of rare earth garnets (Re 3 Al 2 (AlO 4 ) 3 , Re: Gd, Tb, Dy, Er, . . .). These materials crystallize with the body-centered cubic lattice and contain eight molecular units in the conventional unit cell. Group theory predicts 25 Raman active modes for these compounds, while experimentally 19 modes are observed for Lu 3 Al 5 O 12 . As the crystal volume decreases all Raman peaks exhibit pressure coefficients varying from ± ±0.1 to 5.0 cm ± ±1 /GPa. The phonon peak at % 370 cm À1 consists of two components with symmetry A 1g and T 2g , respectively. With increasing pressure a clear separation of the two components is induced. The Raman spectra did not show any evidence of phase transition in the pressure region under investigation.