In this study, the planar flow casting (PFC) technique for producing wide amorphous ribbons of Fe₇₁Si_13.5B₉Nb₃Cu₁Al_1.5Ge₁ alloy is investigated. Various ribbons of the mentioned alloy were produced through applying different values of wheel speed and ejection pressure. In addition, effects of wheel speed (13, 23, and 33 m/s) on the structure, degree of amorphicity, and surface quality of the ribbons were examined. The results showed that the trends of thickness variation with increasing wheel speed and ejection pressure for Fe₇₁Si_13.5B₉Nb₃Cu₁Al_1.5Ge₁ ribbons are in good agreement with what the Bernoulli equation in fluid dynamics predicts for the PFC process. Further, based on x-ray diffraction and differential scanning calorimeter results, it was shown that the degree of amorphicity increases by increasing the wheel speed. Besides, surface roughness measurements and scanning electron …