A micro-Raman study of a Pr0.5Ca0.5MnO3 single crystal and thin films

作者：Mansouri S^*; Charpentier S; Jandl S; Fournier P; Mukhin A A; Ivanov V Yu; Balbashov A

来源：Journal of Physics: Condensed Matter , 2009, 21(38): 386004.

DOI：10.1088/0953-8984/21/38/386004

We present a micro-Raman study of a high quality Pr0.5Ca0.5MnO3 single crystal and thin films on SrTiO3 and LaAlO3 substrates. Ten A(g) and seven B-2g Raman-active modes (simplified symmetry: Pmma space group) have been observed and correlated to charge ordering around T-co = 240 K and antiferromagnetic spin-orbital ordering at T-N similar to 170 K. Our data reveal that coherent Jahn-Teller MnO6 distortions prevail at T < T-N. Moreover, the temperature dependence of the frequency and linewidth of the A(g) mode corresponding to in-plane oxygen atom rotation (similar to 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.

• 出版日期2009-9-23