|
Prepared oxide ferroelectric thin films with a wide range of application prospects in base metals such as Ni, Cu substrate, but technically still faces huge challenges. Among them, the main technical difficulty lies in the control of the interface between the film and the base metal of the oxide ferroelectric. Base metals substrate in the oxide film growth process is easy to form a metal oxide layer, as well as most of the oxide ferroelectric and metal such as Ni, Cu between lattice mismatch, thermal mismatch, diffusion serious problems are will lead to serious degradation of the ferroelectric properties of oxide ferroelectric thin films. Therefore, the study film preparation method, the growth process conditions of base metals substrate the regularity of the structure and properties of the ferroelectric thin film, especially for the control of the interfacial oxide layer, very important to study the performance of the base sheet on the base metals oxide ferroelectric thin film. This article using a pulsed laser deposition (PLD) method, and a polymer assisted deposition (PAD) to BaTiO 3 (BTO) film was prepared on a Ni substrate, of film preparation conditions, especially oxygen pressure, cooling rate, annealing controlled oxidation of the substrate and BTO thin film (001) direction relative diffraction intensity of regulation, and their impact on the film properties. Prepared in the buffer layer is not inserted in the case, the dielectric and good ferroelectric properties BTO film. The results are as follows: 1, for BTO film was prepared using the PLD method on the Ni substrate, when the oxygen gas pressure is increased from 0 to 250 mTorr, resulting in BTO film grain size is increased from 18 nm to 260 nm; dielectric tunability from The 6.5% increase to 26.6%, but the loss is increased from 0.01 to 0.05. BTO thin film layer and then using the first growth in the background vacuum environment hypoxia leads to 250 mTorr oxygen, the dielectric constant is increased by 20%, a 50% reduction in loss of merit factor is increased. Force microscopy (PFM) can see the obvious domain structures. 2, the cooling rate faster (from 3 ℃ / min to 10 ° C / min.) Cause BTO film grain size decreases. Control the oxygen pressure of 250 mTorr, BTO film grain size is reduced from 260 nm to 180 nm. The cooling rate faster suppress the NiO generated. Fast make BTO film (001) peak relative intensity while the cooling rate increased, the dielectric constant increases, the increase of the dielectric tunability, the merit factor increases. 3,600 ℃ oxygen atmosphere annealing treatment can further improve the dielectric constant of the film loss reduced to 11μC/cm 2 2 >. 4, for use PAD method BTO film was prepared on a Ni substrate, when the sintering temperature is higher than 900 ° C, pure oxidizing atmosphere can easily lead to the Ni substrate oxide affect BTO film growth. On PLD method with PAD in the Ni substrate compared the advantages and disadvantages of the growth of ferroelectric thin films.
|