In the era of IoT, big data, and cloud, the demand for large-capacity storage is expected to increase, but it has been pointed out that the limit of recording density will be reached soon.
The research team at the Graduate School of Science, Hiroshima University has succeeded in developing a molecule that exhibits ferroelectricity (memory effect) at room temperature for the first time in the world.Ferroelectricity was generally not expressed in a single molecule, but the world's first demonstration of a "single molecule derivative" (Single Molecule Electret, SME) that exhibits ferroelectricity even in a single molecule. It will be done.By implementing the "SME" developed in this research as a memory, it will be possible to improve the recording density by 1000 times or more compared to the recording density of the ferromagnetic memory currently used for HDDs, etc., so it will be visited in the near future. It can be said that this is an important discovery that can break through the limit of recording density that was supposed to be.
A ferroelectric substance refers to a substance in which the polarization is aligned even without an electric field (spontaneous electrode) and the direction of polarization is reversed by the electric field.By making the direction of this spontaneous polarization correspond to 0 and 1, it can be used as an information recording material.
In this study, a new mechanism that overturns the theory of ferroelectrics causes spontaneous polarization and polarization hysteresis (memory effect) peculiar to ferroelectrics to be exhibited in a single molecule that was originally thought to have no ferroelectricity. I succeeded in making it.This molecule is a cage-like inorganic molecule "Pleyssler-type polyoxometallate" containing terbium ions, and its expression mechanism is different from that of general ferroelectrics based on the conventional ferroelectric theory.In other words, it is a new group of substances that is not bound by the physical limits of the recording density calculated based on the conventional theory, and has the potential to significantly change the information society in the future.
Paper information:[Angewandte Chemie International Edition] Giant Hysteretic Single-Molecule Electric Polarisation Switching above Room Temperature