Multiferroic and enhanced microwave absorption induced by complex oxide interfaces

NiFe_2O_4(NFO)/ZnO composite nanoparticles with different ZnO components were investigated, which were prepared by a simple wet chemical route method. The magnetoelectric coupling between magnetostriction from NFO and piezoelectricity from ZnO was induced by the surface coating NFO nanoparticles of ZnO layer, NFO/ZnO composite showed ferroelectric properties and the remanent electric polarization reached 0.08 μC/cm. Moreover, the changes of resistance at different room temperatures reached about 2% under 3 T magnetic fields comparing with that of zero magnetic fields. Furthermore, multiferroic NFO/ZnO resulted in enhancement of microwave absorption due to magnetoelectric coupling.     

Angular control of multi-mode resonance frequencies in obliquely deposited CoZr thin films with rotatable stripe domains

We investigate the angular-dependent multi-mode resonance frequencies in CoZr magnetic thin films with a rotatable stripe domain structure.A variable range of multi-mode resonance frequencies from 1.86 GHz to 4.80 GHz is achieved by pre-magnetizing the CoZr films along different azimuth directions,which can be ascribed to the competition between the uniaxial anisotropy caused by the oblique deposition and the rotatable anisotropy induced by the rotatable stripe domain.Furthermore,the regulating range of resonance frequency for the CoZr film can be adjusted by changing the oblique deposition angle.Our results might be beneficial for the applications of magnetic thin films in microwave devices.     

Characterization and Magnetic Properties of Iron-Based Alloy Antidot Arrays

Fe29Cerl and Fe19Ni81 antidot arrays, with different dimensions, are prepared with the rf magnetron sputtering method onto the porous alumina substrate. The size and shape of antidot arrays are characterized by scanning electron microscopy. The glancing angle x-ray diffraction patterns of Fe29C071 and FelgNi81 antidot arrays indicate the bcc and fcc structures, respectively. The coercivities of both the alloys show abnormal thickness dependence, which are discussed qualitatively by considering the pinning and the thickness effect to the films.