AbstractA series of M‐type Ba−Sr hexaferrites of composition Ba0.20Sr0.80‐xSmxFe12‐y(Cr0.5Al0.5)yO19 (x=0.00–0.40; y=0.00–0.32) were prepared by solid‐state reaction route. XRD patterns reveals that there is a single magnetoplumbite phase in the hexaferrites with the substitutiom of Sm (0.00≤x≤0.20) and CrAl (0.00≤y≤0.16) contents, while for the hexaferrites containing Sm (x≥0.30) and CrAl (y≥0.24), impurity phase is detected in the structure. The remanence (Br) decreases with increasing substitution content of Sm (0.00≤x≤0.40) and CrAl (0.00≤y≤0.32). With the increase of substitution contents, the intrinsic coercivity (Hcj) increases, while the magnetic induction coercivity (Hcb) first increases, and then decreases. Br has a linear decreasing behavior with increasing temperature from 20 °C to 170 °C. Hcj raises linearly with increasing temperature from 20 °C to 170 °C. The average temperature coefficient of Br (αBr) basically remains constant with increasing substitution content of Sm (0.00≤x≤0.40) and CrAl (0.00≤y≤0.32). The average temperature coefficient of Hcj (αHcj) decreases with increasing substitution content of Sm (0.00≤x≤0.40) and CrAl (0.00≤y≤0.32). The electrical resitivity (ρ) decreases with increasing substitution content of Sm‐CrAl.