Natürlich atomar geschichtet : MAX-Phasen sind ultrastabile Materialien mit einstellbaren Funktionen
MAX-Phasen sind atomar geschichtete, ultrastabile Carbid- oder Nitrid-Verbindungen. Sie sind elektrische Leiter, manche Zusammensetzungen sind selbstheilend, andere magnetisch oder supraleitend. Wie lassen sich diese neuartigen Materialien für die Energieumwandlung und Sensorik nutzen?
MAX phases are naturally atomically layered solids with very different bonds in and between the individual M, A and X layers. This leads to directional dependence of their mechanical, optical, electronic and magnetic properties. They combine the properties of ceramics and metals in one material and thus have great potential for a wide range of applications, from electrochemistry to magnetic materials. Their resistance to oxidation is particularly important, especially in comparison to other metals. Active research in this area will provide many new scientific insights in the coming years, which will certainly give rise to further applications. The magnetic properties of the MAX phases vary depending on the type of magnetic elements contained in them and their concentration, with most of them being so-called Pauli paramagnets. Through partial substitution of elements, materials with long-range magnetic order can be produced without losing other functionalities. MAX phases are also the starting material for 2D MXenes. Chemical etching of the A layers results in thin sheets with a thickness of a few atomic layers. They are characterized by their high conductivity, excellent mechanical strength and versatile applicability in areas such as energy conversion, electronics and sensor technology.