Structure, Morphology, and Properties of Strontium Barium Niobate Thin Films Grown by Pulsed Laser Deposition

摘要

Strontium barium niobate (Sr_xBa_(1-x)Nb_2O_6) thin films with x = 0.61 were grown by reactive Pulsed Laser Deposition and characterized as to their structure, composition, and optical properties. Films were deposited on MgO (001) and fused silica substrates at a wide range of growth rates. A detailed study of film microstructure and surface morphology was performed with x-ray diffraction and atomic force microscopy techniques. Refractive indices of the samples were determined with transmission spectroscopy. Films with excellent texture, and oriented with the c-axis normal to the substrate surface were obtained on the MgO substrates, particularly at lower growth rates. Films grown on fused silica at 700 deg C are at least partially polycrystalline, showing preferred orientation with the c-axis normal to the substrate surface, while those grown at lower temperatures are amorphous. Crystal grain sizes of the films are strongly dependent on both sample growth temperature and laser pulse repetition rate.