Phase Transition In Perovskite LaGaO 3 Crystals Doped With Sr And Mn : Studied By Raman Spectroscopy T. Runka a , M. Głowacki b , M. Berkowski b and M. Drozdowski a a Faculty of Technical Physics, Poznan University of Technology, ul. Nieszawska 13A, 60-965 Poznań, Poland b Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warszawa, Poland INTRODUCTION In recent years perovskite-type LaGa 1-x B x O 3 (where B = Mg, Mn) compounds have been the subject of extended investigations because of either the potential technological applications or the basic interest in solid state physics due to the existence of phase transition [1,2]. Lanthanum gallates doped with Sr and Mn or other transition metal elements are good candidate as anode materials for LSGM-based SOFCs. This paper concerns the investigations LaGaO 3 crystals doped with Sr and Mn ions carried out using Raman spectroscopy. Single crystals of LaGaO 3 doped with Sr and Mn (LSGMn) were grown by the Czochralski method from the melt with compositions: La 1-x Sr x Ga 1-y Mn y O 3 , x = 0.05 y = 0.06, x = 0.075 y = 0.09 and x = 0.1 y = 0.12. EXPERIMENTAL The micro-Raman spectroscopy (µRS) investigations were performed using oriented and non-oriented La 1-x Sr x Ga 1-y Mn y O 3 crystals. The Raman spectra were recorded in spectral range 100 – 900 cm -1 with the resolution better than 2 cm -1 , using as an exciting source ion argon laser operating at λ = 488 nm and near infrared laser operating at λ = 785 nm. During measurements the laser power in both cases was less than 0.3 mW to avoid the local heating of the sample. The temperature measurements were performed using Linkam THMS 600 cooling/heating stage with temperature stability 0.1K. RESULTS AND DISCUSSION In Fig. 1 we present the RT Raman spectra of La 1-x Sr x Ga 1-y Mn y O 3 crystals obtained with 488 and 785 nm wavelength. The absolute intensity of Raman spectra detected with 785 nm excitation is about one order higher than that of 488 nm excitation. The spectra of LaGaO 3 crystals doped with Sr and Mn recorded for 488 and 1129 Downloaded 30 Aug 2010 to 95.108.45.165. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/about/rights_permissions