Goethite and hematite with targeted morphologies dry mixed and cold-pressed with SrCO3, with subsequent sintering to achieve highly aligned hexaferrite. Goethite needles offered the best alignment both magnetically and crystallographically.

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In this experiment, students explore the synthesis and physical property characterization of the magnetic material strontium hexaferrite (SrFe 12 O 19 ). SrFe 12 O 19 crystallites are prepared by a simple but fascinating sol−gel autocombustion synthesis. The prepared powder is compacted into pellets and sintered. With variation of the sintering temperature, it is possible to modify the magnetic properties. The structural properties of the samples are analyzed by powder X-ray diffraction. A tutorial demonstrates for the students how powder X-ray diffraction data from the sample combined with Rietveld refinement can extract phase purity and crystallite size. The magnetic properties are measured using a simple setup with a scale and a strong neodymium magnet; this gives an intuitive understanding of magnetism and how to measure magnetic properties. Additionally, the magnetic properties are measured with a vibrating sample magnetometer and compared to the results obtained using the simple scale method. The lab exercise can be adapted to different levels of education based on the background of the students and the equipment available in the laboratory.