M. Djamal, Ramli, Khairurrijal, F. Haryanto
This paper describes an experimental study on development of giant magnetoresistance material based on cobalt ferrite (CoFe2O4). We have successfully developed a new giant magnetoresistance material based on CoFe2O4 i.e; sandwich (CoFe2O4/CuO/CoFe2O4), spin valve (FeMn/CoFe2O4/CuO/CoFe2O4), and organic giant magnetoresistance (CoFe2O4/Alq3/CoFe2O4) using dc-opposed target magnetron sputtering method. Crystalline structure and morphology of thin films were characterized by X-ray diffraction and scanning electron microscope. The electrical properties were characterized using a four-point probe and magnetic properties were characterized using a vibrating sample magnetometer. In sandwich structure, the giant magnetoresistance ratio maximum are found at room temperature in CoFe2O4/CuO/CoFe2O4 thin film is 70% when CoFe2O4 and CuO layer thickness are 62.5 nm and 14.4 nm, respectively. The maximum of giant magnetoresistance ratio of the spin valve structure obtained is 32.5% at FeMn layer thickness of 45 nm. Meanwhile, in organic giant magnetoresistance the maximum value of the giant magnetoresistance ratio are approximately 35.5% at room temperature.
Institut Teknologi Bandung, Department of Physics, Jl. Ganesa 10, Bandung, Indonesia; Institut Teknologi Sumatera, Department of Physics, Jl. Terusan Ryacudu, Lampung Selatan, Indonesia; Universitas Negeri Padang, Department of Physics, Jl. Prof. Hamka, Padang, Indonesia
