Preparation of Epitaxial Ba0.6Sr0.4TiO3 Ferroelectric Thin Film and Its Dielectric Energy Storage Performance
A Pt/Ba0.6Sr0.4TiO3(BST)/La0.5Sr0.5CoO3(LSCO)ferroelectric capacitor was fabricated on(001)LaAlO3 single crystal substrate using off-axis magnetron sputtering technology.The structure,morphology,and va-rious properties,including dielectric,leakage,and energy storage performance of the BST film,were investigated in detail.The results indicate that the BST thin film is grown epitaxially and has a smooth and dense surface with a root mean square roughness of 1.228 nm.The Pt/BST/LSCO capacitor exhibits excellent dielectric properties with tunability and maximum loss of 73.73％and 0.078 at a frequency of 100 kHz,respectively,as well as lower leak-age current densities(on the order of 10-6 A/cm2).In addition,the BST thin film demonstrates favorable energy storage performance and temperature stability.At a frequency of 10 kHz and an applied electric field of 2 000 kV/cm,the total energy storage density,effective energy storage density,and energy storage efficiency at room temper-ature are 27.01 J/cm3,16.03 J/cm3,and 59.4％,respectively.With increasing temperature up to 105 ℃,the en-ergy storage efficiency can reach as high as 72.2％with an applied electric field of 1 200 kV/cm,which can be at-tributed to the higher temperature promoting the thermal movement of ions,thereby effectively improving the energy storage efficiency.
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