South Africa is one of the world’s main producers of Chromium (Cr). However, the potential of Chromium and its related materials as a socio-economic tool in the improvement of lives have not been optimised in the South African context. This despite the fact that Chromium and its alloys have many unique properties have attracted the interest of the scientific community for many years.
According to Aletta Prinsloo, Professor in the Department of Physics at the University of Johannesburg (UJ), much of the Chromium mined in South Africa is exported without adding much value to it. However, this can be changed in the future considering research findings on the diversity of this metal.
In her professorial inauguration address titled, ‘More than 20 years of Cr based research: A personal perspective’, Professor Prinsloo pointed out that material research into this South African commodity can impact noticeably in many spheres on the long term. Prof Prinsloo’s inaugural address took place in the University’s Council Chambers, Madibeng Building, Auckland Park Kingsway Campus on Tuesday, 6 August 2019.
She sketched some of the paradoxes and puzzles surrounding the study of Chromium-based materials. In her address she emphasized that although Chromium alloys are in general considered to be ‘simple’ metals, these alloys exhibit a great variety of unique properties that continually surprise scientists as boundaries are shifted through modern measurement techniques.
Reflecting on the research done by the Chromium Research Group within the Department of Physics at UJ, Prof Prinsloo was able to showcase that her completed research on Cr based bulk samples, thin films and nanoparticles have resulted in significant contributions to this field. Furthermore, Prof Prinsloo added that the scope for future research incorporating Cr based materials is constantly increasing, with opportunities to not only broaden fundamental knowledge in the arena of magnetism, but also to develop new materials that can find applications in modern technologies.
The address focused on a variety of Chromium alloys. These materials constitute a prototype of a class of model systems that undergo magnetic phase transitions associated with the nesting of the electron and hole Fermi surfaces. The beauty and diversity of the properties of Chromium-based materials originates in the spin-density-wave (SDW) state that is formed when the electron and hole Fermi sheets overlap on cooling through the Néel transition. Research has shown that the magnetic and physical properties of these alloys can be tailored to obtain desired characteristics, utilizing various mechanisms, including doping, the application of pressure or magnetic fields.
Chromium-based research is envisaged to be broadened in the next few years with more work on materials in bulk, thin film and nanoparticle forms, leading to a deeper theoretical understanding of the various factors at play in these diverse alloys and compounds. Planned future investigations will also consider work on core-shell particles that can find applications within the medical and water purification fields, linking this research to the 4IR initiative at UJ.