A study of the magnetic properties of hydrothermally synthesised Sr hexaferrite with Sm substitution

• Published in: Journal of magnetism and magnetic materials Vol. 234; no. 2; pp. 233 - 240
• Main Authors: Wang, J.F., Ponton, C.B., Harris, I.R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2001; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Fine-particle systems; Hydrothermal synthesis; Magnetic properties; Magnetic properties and materials; Physics; Sm substitution; Small particles and nanoscale materials; Sr hexaferrite; Studies of specific magnetic materials; Sm substitution; Hydrothermal synthesis; Sr hexaferrite; Magnetic properties; Samarium oxides; Particle size; Hexagonal ferrites; Magnetization; Transition element compounds; Calcination; Composition effect; XRD; Experimental study; Fabrication property relation; Hydrothermal growth; Strontium oxides; Magnetic particles; Coercive force; SEM; Iron oxides; Microstructure; Chemical synthesis; Saturation magnetization
• ISSN: 0304-8853
• DOI: 10.1016/S0304-8853(01)00366-3

Sm doped Sr hexaferrite particles were synthesised hydrothermally. Post-synthesised calcination with the aim of improving the magnetic properties of as-synthesised particles was conducted at temperatures ranging from 900°C to 1150°C for 2 h in air. The effects of the Sm/Sr ratio and the calcination temperature on the crystallography, particle morphology and magnetic properties of Sm doped Sr hexaferrite were investigated by an X-ray diffractometer, scanning electron microscope and vibrating sample magnetometer. It was found that, unlike transition metal element substitution, Sm substitution does not decrease the hexaferrite particle size. The intrinsic coercivities of Sm doped Sr hexaferrite are significantly higher than those of Sr hexaferrite. It has been observed that Sm substitution can increase the intrinsic coercivity of Sr hexaferrite without causing any deterioration of the saturation magnetisation and remanence. In the Sm/Sr range 1/8–1/2 inclusively, there is little change in the coercivity but a slight fall in both the magnetisation and the remanence.