Magnetoelectric Effect in M-type Hexaferrite Thin Films at Room Temperature

Abstract

Here, for the first time we report M-type magnetoelectric (ME) thin films. The films were deposited by pulsed laser deposition. A single target of magnetoelectric material SrCo2Ti2Fe8O19 was prepared by conventional solid state method. Thin films of this material were deposited using a KrF excimer laser with a wavelength of 248 nm, energy of 400 mJ/pulse and 10 Hz repetition rate. The substrate was placed in 5 cm distance of the target and heated up to 600oC in 200 mTorr of oxygen pressure. The films were annealed at 1050oC in oxygen atmosphere for 1 hour in order to stabilize M-type phase. These thin films were characterized by vibrating sample magnetometer (VSM), ferromagnetic resonance (FMR), X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS). We measured saturation magnetization of 1250 G, g-factor of 2.66 and coercive field of 20 Oe for these magnetoelectric M-type hexaferrite thin films. The magnetoelectric effect was confirmed by monitoring the change rate in remanence magnetization with the application of DC voltage at room temperature and it gave rise to changes in remanence in the order of 12.8% with the application of only 1 V (DC voltage). We deduced a magnetoelectric coupling, ?, of 6.07_10-9 sm-1 in SrCo2Ti2Fe8O19 thin films.