Reduction of electromagnetic interference from mobile devices with high permittivity BaTiO3 and Fe3O4-TiO2 thin film

Multi-stacked layers of micron-thick BaTiO
3
and Fe
3
O
4
-TiO
2
prepared by dip coating has served as an effective electromagnetic shield of 3G network signals from mobile device. There is significant reduction in the transmission of EM signal at 2.0 GHz for acrylic coated with 6µm thick of BaTiO
3
by close to an order of magnitude compared to bare acrylic substrate. The use of multi-stack oxide layers with drying duration of 1 hr at 100°C after each dip coated cycle reduced the extent of cracks generation and enables a uniform thick oxide layers to be coated. The oxide coated acrylic mobile holder can effectively reduce the magnetic field strength of the signal transmitting from the mobile phone and lowered the potential for interference to microwave frequency sensitive device.