Preparation, characterization and dielectric tunability of La2NiMnO6 ceramics

•PVA sol–gel route was used for the synthesis of La2NiMnO6.•The single-phase La2NiMnO6 was prepared successfully at 600 °C.•La2NiMnO6 ceramics show dielectric tunability.•The ɛ–E relation was described by the “multi-polarization mechanism” model.

La2NiMnO6 powders were prepared by using a polyvinyl alcohol (PVA) sol–gel route. Differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were used to characterize the precursors and the derived oxide powders. Single-phase La2NiMnO6 of about 40–50 nm diameters was synthesized at 600 °C for 2 h, without the formation of any intermediate phase. La2NiMnO6 ceramics sintered at 1000 °C had tunability of 28% and 20% at 8 V/mm at 100 kHz and 1 MHz, respectively. The electric field dependence of dielectric constant of the ceramics was well described by using the “multi-polarization mechanism” model.