Amorphous GdTbFeCo magnetic thin films are prepared onto glass substrates by RF magnetron sputtering system from a mosaic target. The effect of sputtering power, sputtering time and sputtering pressure on the magnetic properties of the thin films are investigated by the parameter control method. It is found that when the sputtering power, sputtering pressure and sputtering time of the GdTbFeCo thin Films are 75W, 0.5Pa and 613 second, respectively, the coercivity with per...