Preparation and characterization of thin film CoFe₂O₄/Zn/CoFe₂O₄ by using spin-coating method

Abstract

Research has been conducted on the manufacture of CoFe2O4 / Zn/CoFe2O4 thin films using sol gel-spin coating method. This study aims to look at the effect of rotational speed on optical properties and electrical properties, and to find the highest GMR ratio. Making CoFe2O4 uses Co2+ precursors and Fe2+ precursors with a mole ratio of 1: 2, dissolved with ethyl alcohol. The Zn precursor was made with a concentration of 0.5 M from Powder (CH3COO)2Zn. 2H2O dissolved with ethyl alcohol. The rotation speed variations used are at 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm and 4000 rpm. The thin layer of GMR is made with a sandwich structure. CoFe2O4/Zn/CoFe2O4 thin films with variations in rotational speed were tested for electrical properties using the 4-point probe system method and characterized using X-Ray Diffraction, Scanning Electron Microscopy (SEM), and UV-Vis Specrophotometer. Based on the testing of the electrical properties obtained the lowest resistance and resistivity values at 2000 rpm rotation speed, where the faster the rotational speed is used, the greater the resistance and resistivity values. The highest GMR ratio obtained was 53.5%. Measurement results with Scanning Electron Microscopy (SEM) obtained layer thickness of 3.5 μm.