Thermal expansion of lattice parameters of La 3 Nb 0.5 Ga 5.5 O 14 , La 3 Ta 0.5 Ga 5.5 O 14 and La 3 SbZn 3 Ge 2 O 14

✍ Scribed by Pavlovska, A.; Schneider, J.; Werner, S.; Maximov, B.; Mill, B.; Baetz, C.

• Book ID: 118032847
• Publisher: Oldenbourg Wissenschaftsverlag
• Year: 2003
• Tongue: English
• Weight: 209 KB
• Volume: 218
• Category: Article
• ISSN: 2194-4946
• DOI: 10.1524/zkri.218.3.187.20748

✦ Synopsis

Abstract

The thermal expansion of trigonal La~3~Nb~0.5~Ga~5.5~O~14~ (LNG), La~3~Ta~0.5~Ga~5.5~O~14~ (LTG) and monoclinic La~3~SbZn~3~Ge~2~O~14~ (LSZG) was studied with X-ray powder diffraction technique. The trigonal crystal structures of LNG and LTG are stable under elevated temperature and no phase transition was detected up to 1123 K, whereas the monoclinic LSZG undergoes a phase transition at temperature 523(50) K, presumably to trigonal space group __P__321. The thermal expansion of LNG, LTG and LSZG is anisotropic. This can be explained by the layer structure of title compounds. The mean coefficients in the monoclinic a, b and c directions for LSZG from room temperature to 523(50) K are 8.20, 8.47 and 6.22 [10^-6^/K], respectively. The mean coefficients in the trigonal a and c directions are 8.141 and 6.162 [10^-6^/K] for LNG; 7.653 and 5.344 [10^-6^/K] for LTG from room temperature to 1123 K.