Synthesis and Properties of Dipyridylcyclopentenes

A short and general route to the substituted dipyridylcyclopentenes was explored and several new compounds belonging to this new group of diarylethenes were synthesized. The study of their photochromic and thermochromic properties shows that the rate of the thermal ring opening is strongly dependent on the polarity of the solvent.

Spin Relaxation in Graphene with self-assembled Cobalt Porphyrin Molecules

In graphene spintronics, interaction of localized magnetic moments with the electron spins paves a new way to explore the underlying spin relaxation mechanism. A self-assembled layer of organic cobalt-porphyrin (CoPP) molecules on graphene provides a desired platform for such studies via the magnetic moments of porphyrin-bound cobalt atoms. In this work a study of spin transport properties of graphene spin-valve devices functionalized with such CoPP molecules as a function of temperature via non-local spin-valve and Hanle spin precession measurements is reported. For the functionalized (molecular) devices, we observe a slight decrease in the spin relaxation time ({\tau}s), which could be an indication of enhanced spin-flip scattering of the electron spins in graphene in the presence of the molecular magnetic moments. The effect of the molecular layer is masked for low quality samples (low mobility), possibly due to dominance of Elliot-Yafet (EY) type spin relaxation mechanisms

Enantiomerically pure β-phenylalanine analogues from α–β-phenylalanine mixtures in a single reactive extraction step

An efficient and selective method for the extraction of α-amino acids in preference over their β-isomers using PdCl2(PPh3)2 was discovered, which enables the separation of product mixtures obtained in the enantioselective enzymatic formation of β-amino acids.

Spin Nernst magnetoresistance for magnetization study of FePS3

The magnetization of the antiferromagnetic van der Waals material FePS3 is investigated via the spin Nernst magnetoresisance (SNMR) and spin Seebeck effect (SSE). A heater and Pt detector strips are fabricated on top of a FePS3 flake which generates a temperature gradient in FePS3 and in the Pt detector strips. We are able to detect the SNMR in Pt, which is an interface effect, and detect the SSE response, which is a bulk effect. We conclude that there are uncompensated magnetic moments in FePS3 at the interface with Pt. Via the SNMR we are able to extract the real and imaginary parts of the spin mixing conductance assuming a fully uncompensated top layer. For an in-plane thermal conductivity of 10 W/(mK) and therefore a temperature gradient of 6000 K/m in Pt we find that Gr=1.9±0.06×1013ω-1m-1 and Gi=4.8±0.02×1011ω-1m-1. In addition, the temperature gradient in FePS3 generates a magnon current in FePS3 via the SSE which can be detected by the Pt detector strips. We are able to extract a magnon diffusion length of 1.3±0.5 and 0.5±0.1μm for thermally generated magnons in FePS3 for 40 and 20 nm thicknesses, respectively.</p