César Tejera defens his thesis on teorical Physics: "You can't do science in a hurry"

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César Tejera is defending his PhD thesis this Monday, December 12, at Universidad Complutense de Madrid. Directed by ICMM's researcher Silvia Gallego Queipo, his work is entitled 'Ab-initio study of magnetic properties of complex oxides based on ferrites'. 

"My research is based on contributing, from a theoretical point of view to the understanding of the behavior at the atomic level of magnetic materials, with the aim of improving them", explains the researcher with simple words. "These magnetic materials are everywhere, from energy harvesting to electronic devices. We try to make them more efficient and cheaper", he adds. 

Tejera explains the framework of his Ph.D. thesis: "Permanent magnets are nowadays regarded as essential, meaning they cannot be replaced by other materials, for many different technological applications", he says, and adds: "The most powerful magnets contain rare earth, elements that are at supply risk for the European Union (EU) and other regions, as China controls more than 80\\\\\% of their global production. Besides, mining rare earth is environmentally harmful and causes serious human health problems. This has moved the EU to promote research on rare-earth free magnets, an initiative that perfectly fits with the carbon-neutral goals and European Green Deal".

Within this context, his work "is devoted to the fundamental description of the electronic and magnetic properties of rare-earth free ferrite-based permanent magnets, using ab initio simulations". The young researcher explains that the ultimate objective of this Ph.D. "is to contribute from a theoretical approach to the improvement of the magnetic performance of these materials, as a way to minimize the dependence on critical rare-earth permanent magnets".

As a result of his studies, he has proved as false "a hypothesis that the magnetic properties of nickel ferrites would be improved by introducing Zn atoms into the system". He has also proved that "a combination of two different materials can give rise to an enhancement of the magnetic anisotropy under certain strain conditions". And, what is this for? "This can help the experimentalist to improve the magnetic performance of bicomponent magnets", he says. 

Tejera chose to study at ICMM because he received "a couple of good references". After some years at the Institute of Material Science in Madrid, he is proud of what he has learned: "Research takes a great deal of effort and an enormous amount of time. You can't do science in a hurry". 

"Scientific research based on "the more publications, the better" is not doing any good to science. Luckily, there will always be geniuses pushing the frontiers of science", he finishes. 

-- Ángela R. Bonachera (Communication and Outreach Unit. ICMM)--