en.Wedoany.com Reported - Researchers at Johannes Gutenberg University Mainz (JGU) have developed a novel manganese-based molecular material, raising the operating temperature of molecules used as miniature data storage devices to approximately -132 degrees Celsius. The findings were published in Nature Chemistry. Previously, only iron-based molecular materials could achieve this function, but their operating temperature needed to be maintained between 100 and 130 Kelvin (approximately -173 to -143 degrees Celsius), with the low-temperature requirement leading to high energy consumption and operational complexity. Professor Katja Heinze from the JGU Department of Chemistry stated that the new manganese-based material, in its first attempt, has surpassed all known iron-based molecular materials in related applications, marking a progress in the field of spintronics.

In the field of data storage, the electron spin (magnetic moment, behaving like a bar magnet) of individual ions can be aligned parallel or antiparallel, corresponding to the binary "1" or "0," i.e., high-spin or low-spin states. Iron-based storage devices typically have a maximum operating temperature of 100 Kelvin (approximately -173 degrees Celsius). Previously, a team reported raising this to 130 Kelvin (approximately -143 degrees Celsius), which was considered near the limit of this material system. The JGU team achieved a temperature jump of about 11 Kelvin. JGU Department of Chemistry doctoral student Sandra Kronenberger, who synthesized the new material with support from the Max Planck Graduate Center in collaboration with JGU, noted that manganese can perform as well as, or even better than, iron. Dr. Luca Carrella from the JGU Department of Chemistry measured the magnetic behavior of the new material and believes that while the system is still far below room temperature, this progress represents an important step toward achieving higher operating temperatures in spintronics.

This breakthrough in temperature performance stems from combining manganese with ligands derived from N-heterocyclic carbenes, which form strong bonds with manganese. The strong bonds stabilize the low-spin state while creating a high energy barrier between the two spin states, making both spin states more stable for information storage and capable of withstanding higher temperatures. The "writing" of information is similar to that with iron ions: when manganese ions are irradiated with light, electrons change their spin state, and the material's color shifts from the dark red of the low-spin state to the light yellow of the high-spin state. Heinze stated that after switching, the material's color and magnetic properties persist for a useful period after the light source is turned off, a concept that could provide direction for future digital storage technologies.