Growth and Characterization of Well-Aligned RuO2 Nanocrystals on Oxide Substrates via Reactive Sputtering

Abstract

Well-aligned, densely packed RuO2 nanocrystals (NCs) have been grown on sapphire (SA), LiNbO3 (LNO), and LiTaO3 (LTO) substrates with different orientations via reactive magnetron sputtering using a Ru metal target. The surface morphology and structural and spectroscopic properties of the as-deposited NCs are characterized using field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and micro-Raman spectroscopy (RS). FESEM micrographs reveal that NCs grown on SA(100)/LNO(100) are vertically aligned, whereas the NCs on SA(012)/LTO(012) and SA(110) contain singly and doubly tilted alignments, respectively, with a tilted angle of ∼35° from the normal to the substrates. NCs grown on SA(001) show in-plane alignment with the mosaic structure. The XRD results indicate that the NCs are (001), (101), and (100) oriented on SA(100)/LNO(100), SA(012)/LTO(012)/SA(110), and SA(001) substrates, respectively. A strong substrate effect on the alignment of the ...