Structure and magnetic properties of hexagonal-close-packed Co films deposited by low energy sputtering

Co films of 300 nm in thickness were grown by a low kinetic energy sputtering known as gas-flow-sputtering. X-ray diffraction and electron microscopy were used to study the crystal structure and microstructural development of the films, and a vibrating sample magnetometer was used to measure the magnetic properties. The crystal structure that is dependent on growth temperature, and which is similar to that of bulk transition, has been observed; that is, the structure shows a transition from hcp, through a mixture of hcp and fcc, to fcc with increasing temperature. Single-phased hcp Co film grown at a low temperature has an apparent columnar structure with a preferential orientation of the [00.1] axis normal to the film plane, and has reduced in-plane magnetic anisotropy