Isotropic Nanocrystalline Sm(Fe,Co)11.3Ti0.7 Magnets Modified with B and Zr

•Boron addition slows down the formation of 1:12 structure in melt-spun alloys.•Zr addition speeds up the formation of 1:12 structure in melt-spun alloys.•Together, B and Zr increase coercivity of annealed melt-spun alloys.•Coercivity of bulk magnets was 5.4 kOe with a temperature coefficient of −0.25%/°C.