The properties of thin films of BaScxFe12-xO19 (x=0.4) were determined by structural and magnetic measurements. Films were deposited by pulsed laser ablation deposition onto c-plane sapphire at oxygen pressures between 10 and 100 mTorr. X-ray diffraction measurements showed all films to be single-phase c-axis oriented hexaferrites with expanded c-axis lattice constants compared to x=0 films. Magnetometry measurements showed that all films had the easy axis (c-axis) normal to the film plane, with a mean saturation magnetization value of 3.8 kG. The mean uniaxial anisotropy field value was 10.6 kOe. This ability to adjust the uniaxial anisotropy field in hexaferrite films through selective substitution will be important for future planar microwave devices. © 1999 American Institute of Physics.