title: A micro-Raman study of a Pr(0.5)Ca(0.5)MnO(3) single crystal and thin films.
abstract: We present a micro-Raman study of a high quality Pr(0.5)Ca(0.5)MnO(3) single crystal and thin films on SrTiO(3) and LaAlO(3) 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)∼ 170 K. Our data reveal that coherent Jahn-Teller MnO(6) 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 (∼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.
authors.affiliation: Département de Physique, Université de Sherbrooke, 2500 Boulevard Université, Sherbrooke, Québec J1K 2R1, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Mansouri
authors.forename: S
authors.initials: S
authors.lastname: Charpentier
authors.forename: S
authors.initials: S
authors.lastname: Jandl
authors.forename: P
authors.initials: P
authors.lastname: Fournier
authors.forename: A A
authors.initials: AA
authors.lastname: Mukhin
authors.forename: V Yu
authors.initials: VY
authors.lastname: Ivanov
authors.forename: A
authors.initials: A
authors.lastname: Balbashov