Solvothermal synthesis and magnetic properties of BaFe12−2x(NiTi)xO19 nanoparticles

• It is the first time to synthesize the Ni–Ti substituted BaFe12O19 nanoparticles by solvothermal method.
• The sizes of our sample decrease sharply to nanoscale with increasing x.
• The Ni–Ti codoped samples not only can keep high Ms value effectively, but also can decrease the Hc drastically.

M-type hexaferrites BaFe12−2x(NiTi)xO19 (x=0, 0.05, 0.1, 0.3, 0.5, 0.7, and 0.9) were synthesized by the solvothermal method. X-ray diffraction (XRD) analysis reveals that the samples are of pure-phase with the space group of p63/mmc. As the Ni–Ti substitution level increases from x=0 to 0.9, the results of field-emission scanning electronic microscopy indicate that the particles are agglomerated and the mean particle size decreases. With the increase in substitution concentration x, the saturation magnetization increases first, and then declines slowly, whereas the coercivity decreases gradually. The variation of magnetic properties can be explained by the effects of Ni–Ti substitution. The results above indicate that our samples have positive effects on high density perpendicular recording.