| 초록 |
Magnetostriction effect is the change of mechanical properties in magnetic materials under external magnetic field; it has been studied for possible applications in various technological fields such as actuators. In this study, we focused on fabricating multilayered magnetocapacitor with the highest magnetostrictive material Ni0.98Co0.02Fe2O4. To fabricate magnetocapacitor, Ni0.98Co0.02Fe2O4(NCFO)/BaTiO3(BTO)/Ni0.98Co0.02Fe2O4(NCFO) sandwitch type multilayer thin films were deposited on Pt/TiO2/SiO2/Si(100) substrates by using Pulsed Laser Deposition(PLD) system with a KrF excimer laser (λ = 248nm). The multilayered thin films with NCFO(20, 60 and 150 nm)/BTO(100, 300 and 1000 nm)/NCFO(20, 60 and 150 nm) were studied for their crystal structure and interface microstructure as well as magnetic and electrical properties by using x-ray diffractometer (XRD), atomic force microscope (AFM), auger Electron Spectroscopy(AES), high resolution transmission electron microscope (HR-TEM), and field-emission scanning electron microscopy(FE-SEM), vibrating sample magnetometer (VSM) and aglient 4284A LCR meter, respectively. In this paper our study suggests the possibility of enhanced magnetocapacitance under magnetic field by controlling interfacial compressive/tensile stress of thin film. It is necessary to establish the number of variables to determine the fcmc factors in capacitance. Furthermore we revealed that the thickness of ferromagnetic and ferroelectric is significant variables of fcmc factors. |
