Tereza Havlíková has been working for three years at CEITEC BUT in the Advanced Multifunctional Ceramics group. There, she is developing a new type of transparent ceramic materials that may be used in optics and photonics. Her aim is to find the optimal composition and technological preparation process for ceramic compounds with maximum transparency and photoluminescence – the ability to emit light after irradiation.

She focuses on so-called high-entropy materials, whose use in transparent ceramics is still a novelty. “Simply put, it’s about combining multiple elements into a single crystalline structure. A higher number of elements brings greater entropy – or disorder – and thanks to it, the material gains a greater driving force to stabilize even under unusual conditions,” the scientist explains.

Existing studies show that these materials may exhibit interesting mechanical or superconducting properties. The current question is whether they also offer benefits for optics. “By combining atoms of different sizes, the crystal lattice becomes distorted (deformed), which leads to a shift or change in the shape of the emission spectrum. This can not only improve efficiency in existing technologies but also expand the range of possible applications,” Havlíková adds.

Transparent ceramics are used, for example, as a medium for lasers or in lighting technology. They also hold great potential in the field of scintillation detectors – such as for X-rays or electron microscopes. “The material can capture X-ray radiation and convert it into the visible spectrum. These are currently the most likely applications, but development may bring further possibilities,” she says.

Her research focuses on materials with a garnet structure, into which she adds rare-earth ions – elements from the bottom part of the periodic table, little known to the public, but with specific luminescent and magnetic properties. “Each element reacts differently. Some interfere with each other, while others complement one another. The challenge is to find five that won’t conflict and ideally will have a synergistic effect,” she describes.

Currently, the scientist is trying to find the ideal chemical composition with the best optical properties. Next, it will be crucial to ensure the optical purity of the material. “Any impurities or defects can scatter light and reduce the material’s ability to transmit it,” she explains.

Tereza Havlíková is delighted to have received the Brno PhD Talent scholarship. “Transparent ceramics are very demanding to prepare. It’s a complex process where you need to control every step – from synthesizing chemically pure powder to advanced sintering. It’s a challenge, but that’s exactly what I enjoy about it,” she concludes.


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