Low Dielectric Loss and Good Dielectric Thermal Stability of xNd(Zn_1/2Ti_1/2)O₃–(1−x)Ba_0.6Sr_0.4TiO₃ Thin Films Fabricated by Sol–Gel Method

Abstract

xNd(Zn1/2Ti1/2)O3–(1−x)Ba0.6Sr0.4TiO3 (xNZT–BST) thin films were fabricated on Pt/Ti/SiO2/Si substrates by sol–gel method with x = 0, 3%, 6%, and 10%. The structures, surface morphology, dielectric and ferroelectric properties, and thermal stability of xNZT–BST thin films were investigated as a function of NZT content. It was observed that the introduction of NZT into BST decreased grain size, dielectric constant, ferroelectricity, tunability, and significantly improved dielectric loss and dielectric thermal stability. The corresponding reasons were discussed. The 10%NZT–BST thin film exhibited the least dielectric loss of 0.005 and the lowest temperature coefficient of permittivity (TCP) of 3.2 × 10−3/°C. In addition, the figure of merit (FOM) of xNZT–BST (x = 3%, 6%, and 10%) films was higher than that of pure BST film. Our results showed that the introduction of appropriate NZT into BST could modify the dielectric quality of BST thin films with good thermal stability. Especially for the 3%NZT–BST thin film, it showed the highest FOM of 33.58 for its appropriate tunability of 32.87% and low dielectric loss of 0.0098.

Investigation on preparation and electric field tunable dielectric properties of novel bismuth magnesium niobate transparent capacitors for opto-electronic devices

“…In recent years, much attention has been devoted to the development of tunable dielectric materials for electric eld controlled, frequency-agile phase shiers and lters operating in the microwave regime. [1][2][3][4] Ba x Sr 1Àx TiO 3 (BST) thin lms have been intensively investigated due to their large tunability. 5,6 However, high dielectric loss in the microwave region strongly inhibits their industrial applications.…”

“…There are numerous deposition techniques used to grow dielectric oxide thin lms including molecular beam epitaxy (MBE), 1,18 sol-gel processing, 2,3,11,19 magnetron sputtering, 5,8 metal-organic chemical vapor deposition (MOCVD), 20 chemical solution deposition (CSD) 21,22 and pulsed laser deposition (PLD). 10,23 Among these fabrication methods, magnetron sputtering is considered to be the most favorable deposition method to obtain highly uniform lms even on polycrystalline substrates at high deposition rates.…”