Effect of substrate on the dielectric properties of bismuth magnesium niobate thin films prepared by RF magnetron sputtering

• The BMN thin films were prepared by rf magnetron sputtering.
• The BMN film with large tunability, low loss was achieved.
• The effect of the substrate on dielectric properties was explained.
• ITO glass was proved to be the best option for BMN thin film capacitors.

The Bi1.5MgNb1.5O7 (BMN) thin films were deposited on ITO/glass, FTO/glass and Pt/Si (100) substrate by rf magnetron sputtering. The dielectric properties of BMN thin films on different substrates were investigated. All the BMN thin films showed cubic pyrochlore structure with (222) preferred orientation. The BMN thin film deposited on ITO glass exhibited dielectric constant of 109, low dielectric loss of 0.0013 at 1 MHz, and maximum tunability of 34% at the bias field of 1.2 MV/cm, which is better than that prepared on FTO/glass and Si substrate. The leakage current of BMN thin film on different substrates was also studied and a possible explanation was proposed. These results suggest that the ITO/glass is a promising option substrate for better properties of BMN thin film.