New monolayer material adds organic flexibility to spintronic technology

By using the spin of electrons to process and store digital information, the field of spintronics is poised to advance a range of technologies, including memory storage and photovoltaics. To date, most spintronic devices use inorganic materials, but thin films with organic components have shown a degree of flexibility and complexity that lend them to use for spintronic devices with tunable electrical properties. One group has found a way to bring these features together into a single device.

Hong et al. have reported a demonstration of a spintronic platform that is capable of both electric and magnetic responses. Creating an organic/inorganic hybrid monolayer spacer with 1,4- benzenedimethanethiol (BDMT), the authors created a heterostructured material that could both uses the magnetoresistive effect that allows sensor to endure rugged environments and the electric-history dependent resistance that allows spintronic devices to act as tunable memory storage devices.

“We overcome the technical difficulty of successfully preparing a large area of well-ordered molecular-level organic thin film on the inorganic ferromagnetic underlayer, and bring both electric and magnetic nonvolatile advantages into one device,” said Minn-Tsong Lin, an author on the paper.

The group’s monolayer was constructed through a process of self-assembly in which an organic spin valve was stacked in sequence with nickel-iron and cobalt-iron alloys.

After confirming that the BDMT layer self-assembled correctly using X-ray photoelectron spectroscopy, the team found that spin valves allowed electrical resistance to undergo types of non-volatile switching that is present in magnetoresistive and the memristive switching.

According to Lin, the platform could allow for multi-functional molecular spintronics in the future, with applications in electric, magnetic and even optic manipulation.

Source: “A multifunctional molecular spintronic platform with magnetoresistive and memristive responses via a self-assembled monolayer,” by Jhen-Yong Hong, Shih-Hang Chang, Kui-Hong Ou Yang, Piin-Chen Yeh, Hung-Wei Shiu, Chia-Hao Chen, Wen-Chung Chiang, and Minn-Tsong Lin, Journal of Applied Physics (2019). The article can be accessed at https://doi.org/10.1063/1.5057893 .