Microstructure and magnetic properties of the FeTaCN nanocrystalline thin films.

FeTaCN films were deposited on quartz substrates by cosputtering of Fe and TaC targets at room temperature with different N[SUB2] flow rate ratios in the sputtering gas. The as-deposited films were postannealed in vacuum for 30 min at various temperatures. The effects of annealing temperature on the N[SUB2] flow rate ratio and film thickness on the magnetic properties and microstructure of the film were investigated. X-ray diffraction and transmission electron microscopy analyses show that the as-deposited FeTaCN film has a nanocrystalline structure or mixing phases of nanocrystalline and amorphous. Nanocrystalline as-deposited film with good soft magnetic properties (in-plane coercivity Hc∥= 1∼2 Oe and 4πMs=12-14kG) can be obtained by controlling the N[SUB2] flow rate ratio and film thickness. The soft magnetic properties can be improved by postannealing the as-deposited film at 200-300 °C as the N[SUB2] flow rate ratio is higher than 5 vol %. For the Fe[SUB71.03Ta[SUB 6.1]C[SUB 7.2]N[SUB 15.67] film, the Hc∥ value decreases as the film thickness is increased when the annealing temperature is lower than 400 °C. After annealing at 300 °C, its Hc∥ is about 3.57 Oe as the film thickness is 50 nm and Hc∥ will decrease to 0.18 Oe as the film thickness is increased to 1000 nm. [ABSTRACT FROM AUTHOR]