Scientists at IMDEA Nanociencia are working on the development of materials whose properties can change as easily as we flip a switch. They focus on joining molecular switching (spin transition), electrical transport properties and porosity in the same material. Such materials have an enormous potential to host gas molecules, such as carbon dioxide or hydrogen, and feature responsive properties in the presence of these gases.
In their latest work, researchers report on a metal organic framework (MOF) material that exhibits spin crossover (SCO) behavior, i.e., it can change its magnetic state in response to an external stimulus. This is of enormous interest to the development of electronic applications such as data storage or sensors, as the electrical transport properties depend directly on the spin state of the material.
Furthermore, the researchers also found that the miniaturization of the SCO-MOF into nanometer-sized crystals did not alter its electrical properties, an advantage because as the surface-to-volume ratio increased, so did its sensing capabilities.
This research, published in Small, is the result of a collaboration between scientists led by Dr. Sánchez Costa (IMDEA Nanociencia) and Dr. Sañudo (University of Barcelona).
To confirm the structural integrity of the SCO-MOF nanocrystals, the team used an advanced technique based on electron diffraction (MicroED), performed at the National Center for Biotechnology (CNB-CSIC). This technique allowed them to analyze the atomic arrangement of the nanocrystals and compare them with their macroscopic counterparts.
Their findings revealed that the nanocrystals retained both their crystal structure and their charge-carrying properties, suggesting that MOFs could be miniaturized without compromising their functionality. In other words, nanostructuring transforms the crystals into better sensors.
This scientific advance opens up exciting possibilities for MOF networks in next-generation nanotechnologies. This study represents a significant step towards the integration of MOF materials into cutting-edge technological applications, where precise control over the properties of the material at the nanoscale is crucial.
