The effect of Ce doping on the structure, surface morphology and magnetic properties of Dy doped-yttrium iron garnet films prepared by a sol-gel method

Cerium substitute Y2.8-xDy0.2CexFe5O12 (x=0, 0.2, 0.25, 0.3, 0.35) films have been prepared on quartz substrates by a simple sol-gel method and followed by a spin-coating technique. The crystalline structures, surface and magnetic properties of the films has been investigated by an X-ray diffractometer (XRD), a field emission scanning electron microscope (FESEM), an atomic force microscope (AFM) and a vibrating sample magnetometer (VSM). The XRD analysis revealed that the films have garnet structure. The lattice parameter increased as Ce content was increased up to 0.25 due to the Ce3+ ions completely substituted for Y3+ ions. For films x >= 0.3, the lattice parameter decreased. The FESEM results showed that the average grains were small, ranging from 11 to 14 nm and the thickness of films increased with the increment of Ce contents. VSM results for both in and out-plane magnetic measurement showed the film with x=0 has the highest saturation magnetization (M-s) values. With the increment of Ce contents, the Ms of films decreased due to the substitution of Ce3+, Dy3+ ions in the c-site. For films x >= 0.3 the reduction of Ms values was due to the presence of CeO2 in the film. The films with x=0-0.25 exhibited increases in He values. The improvement of coercivity value, small grain size and high crystalline structure of film with x=0.25 has a potential to be used in magneto optical (MO) memory storage applications. (C) 2016 Elsevier B.V. All rights reserved.