• Universitat de València
• Universidad Autónoma de Madrid

• Tomás Torres Cebada
• Gema de la Torre Ponce
• Carolina Ruiz Ganivet
• Beatriz Ballesteros Moyano

Single-molecule magnets (SMMs) are metal-organic complexes with a purely unimolecular origin that exhibit magnetic hysteresis below a certain temperature (blocking temperature). The design and synthesis of new SMMs is an emerging field with great future prospects due to their potential applications in spintronics, such as high-density data storage and quantum computing processes. However, one of the most important limitations for the real use of SMMs is their low blocking temperatures.

There is currently a growing interest in exploring the possibilities of modulating the SMM behaviour of Tb(III) bisphthalocyaninates. All single-molecule magnetism studies on Tb(III) bisphthalocyaninates have been carried out with homoleptic derivatives, i.e. with the same substitution pattern on both phthalocyanines, while heteroleptic derivatives, i.e. with different substituents on each of the phthalocyanines, have remained unexplored so far.

Researchers from the Universitat de València and the Universidad Autónoma de Madrid have developed a new type of monomolecular magnets (SMMs), based on heteroleptic TB(III) bisphthalocyaninates.

The differential substitution in the peripheral positions of the two phthalocyanine rings composing the Tb(III) complex allows to improve the relevant parameters of the magnetic behaviour of these complexes - such as the spin reversal barrier and the lock temperature - with respect to unfunctionalised Tb(III) bisphthalocyaninates or homoleptic substituted derivatives. This substitution has improved the potential of Tb(III) bisphthalocyaninates in real molecular spintronics applications.

Spintronic devices could offer higher data processing speeds, lower power consumption and many other advantages compared to conventional chips, including the ability to perform quantum computing. Potential applications of SMMs in spintronics include quantum computing, high-density data storage devices and magnetic cooling, among others. These applications are of particular interest in the electronics sector.

The main advantages provided by the invention are:

• Higher spin reversal barrier values, improving the behaviour of the material as SMMs.
• Higher lock temperature values, allowing use as SMMs at more suitable operating temperatures.

• Patent granted