Raman spectra in epitaxial thin films $L{a}_{1-x}C{a}_{x}Mn{O}_3$ (x = 0.33, 0.5) grown on different substrates

Abstract

Raman spectra of LCMO films grown on LAO (001), STO (001), and MgO (001) substrates were studied at different temperatures. The effect of temperature, doping level and strain on Raman spectra are discussed in detail. With decreasing temperature, the changes of Raman spectra are correlated with the disorder-order transition, shuch as: paramagnetism to ferromagnetism, and charge-ordering. The strain induced by lattice-substrate mismatch affects the Raman spectra strongly. The mode induced by disorder of oxygen defects is apparently observed in $L{a}_{0.67}C{a}_{0.33}Mn{O}_3$ film on STO due to the larger tensile strain. While this mode can not be seen in the Raman spectra for the films on LAO and MgO. A strong unsigned mode at about 690 $c{m}^{-1}$ is observed in all films except for $L{a}_{0.67}C{a}_{0.33}Mn{O}_3$ film on LAO, which is not observed in bulk sample easily. It suggests that the mode is closely related to the strain.

10 pages, 6 figures

References in corpus (9)

• Double Exchange Alone Does Not Explain the Resistivity of $L{a}_{1-x}S{r}_{x}Mn{O}_3$
• Cooperative Jahn-Teller Effect and Electron-Phonon Coupling in $L{a}_{1-x}{A}_{x}Mn{O}_3$
• Charge ordered ferromagnetic phase in La0.5Ca0.5MnO3
• Raman phonons as a probe of disorder, fluctuations and local structure in doped and undoped orthorhombic and rhombohedral manganites
• Colossal magnetoresistive manganite thin films
• Strain driven charge-ordered state in La${}_{0.67}$Ca${}_{0.33}$MnO${}_3$
• Two-phase behavior in strained thin films of hole-doped manganites
• Determinative Role of the Jahn-Teller Disorder in the Raman Scattering of Mixed-Valence Manganites
• Orbital order induced metal-insulator transition in (La,Ca)MnO3

Cited by in corpus (1)

• Thin Film Substrates from the Raman spectroscopy point of view