In this thesis the compounds Fe5SiB2 and Fe5PB2 have beensynthesized via high temperature synthesis, including arc melting anddrop synthesis. The structure for both compounds are of Cr5B3 typewith the space group I4/mcm. The cell parameters were refined toa = 5.5533 Å and c = 10.3405 Å for Fe5SiB2 and a = 5.4903 Å andc = 10.3527 Å for Fe5PB2. The saturation magnetization at roomtemperature for Fe5SiB2 has been measured to 138.8 Am2/kg and theanisotropy constant has been estimated to 79 kJ/m3. Theferromagnetic properties and the high anisotropy constant makesthese materials promising as permanent magnet materials, but moreinvestigations are necessary.