Univ.-Prof. Dr. Hubert Huppertz
Solid State Chemistry
The research interests in the solid state chemistry section of the department are dedicated to the explorative synthetic discovery of new compounds in the substance classes of borates, fluoride-borates, boro-germanates, boro-gallates, gallates, borate-nitrates, gallium-oxonitrides, rare earth molybdates, intermetallic compounds, and borides. Advanced synthetic approaches are used under ambient and high-pressure conditions, e.g. using a high-frequency furnace or a high-pressure multianvil equipment. Next to standard solid state synthesis, also molecular precursors are used to aim for new compounds. Primarily, the structure elucidation of the unknown compounds is of interest. Further on, the continuative development and application of these novel materials lies in the focus of our work, including aspects of ionic conductivity, optical properties, non-linear optical behavior, luminescence, mechanical properties, thermal stability, and magnetism.
Solid state chemistry in the Department of General, Inorganic and Theoretical Chemistry focuses on the synthesis, characterization, and application of solid materials with a wide range of chemical compositions and structures. Structure-property-relationships help in understanding how the atomic or molecular structure of a material influences its physical and chemical properties. This again helps in predicting the behavior of materials and in designing specific materials with desired properties. Overall, solid state chemistry aims to advance our understanding of solid materials and to develop new materials with enhanced or novel properties for a wide range of scientific, industrial, and technological applications.
High-frequency furnace for solid state synthesis
Over the past 80 years, the implementation of the parameter pressure into solid-state chemistry has led to remarkable enlarged synthetic possibilities. However, this field, studied from solid-state chemists with its spectrum of compounds and reactions so far, is really narrow, being just a beginning. Compared to the quite easily manageable thermodynamic parameters of temperature and composition, high-pressure conditions are technically much more demanding. The technical development of sophisticated high-pressure cells, especially in the multianvil sector, improved the synthetic possibilities in materials chemistry (hard materials) and mechanical engineering. The focus of our research is on the discovery of new materials under extreme conditions of pressure and temperature.
Multianvil press for high-pressure synthesis
Phosphors for the ever growing LED-lighting sector are an highly important research field in the current research of solid state chemistry. Within this class of materials, europium-activated phases have emerged as a promising substance class for inorganic phosphors with some of them, such as β-SiAlON, RE2Si5N8:Eu2+ (RE = Ca, Sr, Ba), and CaAlSiN3:Eu2+, becoming standard phosphors in the industry. Recent developments, such as the discovery of SLA and SALON, also demonstrated that there is still much potential within this substance class and the number of Eu2+ based phosphors is still increasing. So, our research focus lies on the discovery and characterization of new phosphors for a potential application in LED's.
Typical inorganic phosphors for LED's.