Quantitative analysis of pinning-hardened intrinsic coercivity of Sm(CoFeCuZr)z (z = 7.0–7.8) high-temperature permanent magnets

•Sm(CobalFe0.14Cu0.08Zr0.027)z magnets were prepared with z ranging from 7.0 to 7.8.•The volume fraction of cell boundary phase decreases with increasing z.•Cu content increases from 11.2 at% to 27.7 at% with z increases from 7.0 to 7.8.•The intrinsic magnetism of 1:5H and 2:17R phases at high temperatures are obtained.•The intrinsic coercivity of Sm(CoFeCuZr)z alloys were calculated quantitatively.