Fabrication And Characterization Of Barium Titanate Thin Film On Polycrystalline Nickel Substrate

Abstract

Ferroelectric BaTiO₃(BTO) thin films were deposited on polycrystalline nickel disks and silicon wafer substrates by rf magnetron sputtering. Nickel oxide (NiO) and nanocrystalline nickel (nc-Ni) layers were used as interfacial buffer layers. Microstructural studies with X-ray diffraction and transmission electron microscopy reveal that the BTO films deposited at temperatures lower than 700℃ have an amorphous structure. However, the BTO films sputtered at temperatures higher than 700℃ are partially crystalline. BTO films have a good and continuous interface with both interfacial layers with no interdiffusion or reaction with the substrates. In the case of BTO deposition with nc-Ni interlayer at higher deposition temperature of 800℃, a thin NiO layer forms between the nc-Ni and BTO films. Having nc-Ni as an interfacial layer enhances surface morphology and decreases surface roughness. This study shows that nc-Ni can act as a proper interfacial layer between a ceramic like BTO and the metallic substrates and is a better alternative for NiO buffer layer.