Program Highlights

Control of Spin State at the Molecular Level  

Xiaoshan Xu, Jian Zhang, and Peter Dowben 
Nebraska MRSEC

Axel Endesr 
University of Bayreuth, Germany

Spin-crossover molecules exhibit two non-equivalent spin states, known as low-spin and high-spin states, which can be controlled by external stimuli. This property makes the spin-crossover molecules candidate building blocks for molecular spintronic devices. An additional functionality comes from the coupling between electric and magnetic dipole moments in these molecules.
Nebraska MRSEC researchers have discovered that this coupling allows stabilizing a specific spin state in an iron-based spin-crossover complex. Using interface interactions arising from strongly dipolar zwitterion molecules, they showed a reversible control of the spin state at room temperature. This is finding is important because it may provide a route to molecular electronics that is printable, flexible inexpensive, and nonvolatile. Such molecular electronics could have a great societal impact, by permitting high density memory on something as small and compact as a piece of plastic the shape of a credit card. Especially if the memory aspects are retained in the absence of power.
P. Costa, G. Hao, A. T. N'Diaye, L. Routaboul, P. Braunstein, X. Zhang, J. Zhang, B. Doudin, A. Enders, and P. A. Dowben, “Perturbing the Spin Crossover Transition Activation Energies in Fe(H₂B(pz)₂)₂(bipy) with Zwitterionic Additions,” J. Phys.: Condens. Matter 30, 305503 [5pp] (2018).

This research is supported by the National Science Foundation, Division of Materials Research, Materials Research Science and Engineering Program, Grant DMR-1420645.

A schematics of a reversible control of the spin state of the iron-based spin-crossover complex [Fe{H₂B(pz)₂}₂(bipy)] in the presence of a strongly dipolar zwitterionic molecule.