Tunable perpendicular magnetic anisotropy in GdFeCo amorphous films

► We measure the magnetic anisotropy of amorphous GdxFe93−xCo7 films. ► The magnetization was controlled by varying the composition and temperature. ► At room temperature a large PMA with coercivity of 6.6 kOe was achieved. ► The PMA has a structural origin consistent with the atomic-scale anisotropy.