Sol-Gel Derived La0.7Sr0.3MnO3 Thin Films by Pulsed Laser Deposition

Abstract

La 0.7 Sr 0.3 MnO 3 (LSM) nancomposite was synthesized using sol gel method at 600 ºC. The structure and elemental analysis were confirmed by X-ray diffraction (XRD) and energy dispersive X-Ray (EDX) respectively with rhombohedral crystal structure. High resolution transmission electron microscope (HR-TEM) imaging showed that the prepared LSM has uniform shape with particle sizes ranging between 5 and 95 nm, and lattice fringes also displayed the rhomobhedral structure. Thin films of LSM with 97 nm were deposited on clean Si (100) single crystal substrate by PLD using Nd:YAG (1,064 nm) with 10 Hz repetition rate and 6 ns pulse duration at room temperature in high vacuum of ~6 × 10 -6 torr. LSM films were annealed at temperatures of 400, 600, 800 and 1,000 ºC for 2 h. The XRD indicated that crystallization is enhanced by increasing annealing temperature. Additionally, grain size was increased by rising annealing temperature as indicated from field emission scanning electron microscope (FESEM) imaging. The average roughness (R a ) and root mean square roughness (R q ) were decreased by increasing annealing temperature up to 600 ºC then increased by further temperature increasing as showed by atomic force microscope (AFM) images. Raman spectra were recorded in wave numbers 100-1,000 cm -1 and all major peaks appeared at annealing temperature 1,000 ºC.