Enhanced electron spin lifetime

[mhlndm]

I am developing a cathode for studying the microwave induced magnetic isotope effect (MIMIE) in electrolytic reactions. My premise is that a cationic species and an electron donated by a cathode can be considered as a "quasi-radical pair," and that resonant magnetic pumping of the quasi-radical pair can be done to spin lock the pair, thus preventing reduction of the cationic species. If a particular isotopologue can be selectively spin locked, then an isotope selective reduction of another isotopologue could occur.

The cathode is a flat conductor with an orthogonally applied DC magnetic field that provides Zeeman splitting. A microwave current is applied to the conductor to produce a resonant magnetic field at the surface of the cathode. My understanding is that in most metals, spin relaxation occurs in the picosecond timeframe, whereas in semiconductors spin relaxation can be on the order of a microsecond. It appears that spin relaxation is largely a function of spin-orbit coupling. Can anybody suggest a coating or compound that can be applied to a copper or gold cathode, or adsorbed from an electrolyte, so that the spin lifetime of donated electrons could be enhanced?

Thanks,

mhlndm

 

[eljose79]

Dear mhlndm,

Thank you for sharing your interesting research on the microwave induced magnetic isotope effect (MIMIE) in electrolytic reactions. Your premise of using a "quasi-radical pair" to prevent reduction of cationic species through spin locking is intriguing.

In order to enhance the spin lifetime of electrons donated from the cathode, there are a few potential options that come to mind. One possibility is to use a coating or compound that has a strong spin-orbit coupling. This could potentially slow down the spin relaxation process and increase the spin lifetime of the electrons. Examples of compounds with strong spin-orbit coupling include transition metal complexes and heavy metals like platinum or palladium.

Another option is to use a coating or compound that can act as a spin filter, selectively allowing electrons with a specific spin orientation to pass through while blocking others. This could potentially enhance the spin lifetime of the selected electrons. One example of such a compound is graphene, which has been shown to have a long spin lifetime due to its unique electronic structure.

Additionally, you may want to consider the effect of temperature on spin relaxation. Lower temperatures can often slow down spin relaxation processes, leading to longer spin lifetimes. Therefore, using a cryogenic environment or a cryoprotectant coating on the cathode may also be worth exploring.

I would also suggest further investigating the specific mechanisms of spin relaxation in your system and identifying any potential factors that may be contributing to it, such as impurities or defects in the cathode material.

I hope these suggestions are helpful in your research. Best of luck with your experiments!

 

[charng]

I find your research on the microwave induced magnetic isotope effect (MIMIE) in electrolytic reactions to be very interesting. Your premise of using a resonant magnetic pumping technique to spin lock a quasi-radical pair and prevent reduction of the cationic species is a unique approach.

Regarding your question about enhancing the spin lifetime of donated electrons, I would suggest exploring the use of spin-orbit coupling inhibitors. Spin-orbit coupling is known to play a major role in spin relaxation, so inhibiting this process could potentially increase the spin lifetime of the electrons on the cathode surface.

One possible coating or compound that could be applied to the cathode is a thin layer of graphene. Graphene has been shown to have strong spin-orbit coupling, which can be reduced by doping it with certain elements like nitrogen or fluorine. This could potentially enhance the spin lifetime of the donated electrons on the cathode.

Another approach could be to use a molecular coating or adsorbate on the cathode surface that has a high spin-orbit coupling constant. This could effectively reduce the spin relaxation rate of the donated electrons and enhance their spin lifetime.

In conclusion, I think exploring the use of spin-orbit coupling inhibitors, such as graphene or molecular coatings, could potentially enhance the spin lifetime of donated electrons on the cathode and improve the selectivity of your MIMIE studies. However, further experimental research and testing would be needed to determine the most effective approach for your specific system.