|Titre||A micro-Raman study of a Pr0.5Ca0.5MnO3 single crystal and thin films |
|Type de publication||Journal Article |
|Nouvelles publications||2009 |
|Auteurs||Mansouri S, Charpentier S, Jandl S, Fournier P, Mukhin AA, Ivanov YV, Balbashov A |
|Journal||Journal of Physics: Condensed Matter |
|Pagination||386004 (6pp) |
|Résumé||We present a micro-Raman study of a high quality Pr0.5Ca0.5MnO3 single crystal and thin films on SrTiO3 and LaAlO3 substrates. Ten Ag and seven B2g Raman-active modes (simplified symmetry: Pmma space group) have been observed and correlated to charge ordering around Tco = 240 K and antiferromagnetic spin-orbital ordering at TN[?] 170 K. Our data reveal that coherent Jahn-Teller MnO6 distortions prevail at T$<$TN. Moreover, the temperature dependence of the frequency and linewidth of the Ag mode corresponding to in-plane oxygen atom rotation ([?]268 cm[?]1) is analyzed within a polaron-like scheme that reflects a strong charge ordering to lattice coupling. The close similarities between the single crystal and the thin films' phonon evolution confirm that the thin films growth conditions have been optimized.