Advantages of Prefabricated Tunnel Junction-Based Molecular Spintronics Devices

Abstract

Molecule-based devices may govern the advancement of the next generation's logic and memory devices. Molecules have the potential to be unmatched device elements as chemists can mass produce an endless variety of molecules with novel optical, magnetic and charge transport characteristics. However, the biggest challenge is to connect two metal leads to a target molecule (s) and develop a robust and versatile device fabrication technology that can be adopted for commercial scale mass production. This paper discusses distinct advantages of utilizing commercially successful tunnel junctions as a vehicle for developing molecular spintronics devices. We describe the use of a prefabricated tunnel junction with the exposed sides as a testbed for molecular device fabrication. On the exposed sides of a tunnel junction molecules are bridged across an insulator by chemically bonding with the two metal electrodes; sequential growth of metal-insulator-metal layers ensures that separation between two metal electrodes is controlled by the insulator thickness to the molecular device length scale. This paper highlights various attributes of tunnel junction-based molecular devices with ferromagnetic electrodes for making molecular spintronics devices. We strongly emphasize a need for close collaboration between chemists and magnetic tunnel junction (MTJ) researchers. Such partnerships will have a strong potential to develop tunnel junction-based molecular devices for futuristic areas such as memory devices, magnetic metamaterials, high sensitivity multi-chemical biosensors, etc.

Paramagnetic molecule induced strong antiferromagnetic exchange coupling on a magnetic tunnel junction based molecular spintronics device

“…(MSDs) have attracted worldwide attention due to their potential to revolutionize logic and memory devices [1,2]. A typical MSD is comprised of two ferromagnetic (FM) electrodes-coupled by molecular channels [3,4]. Molecular channels with a net spin state are the basis of a large number of intriguing studies [5], which were either observed experimentally [6,7] or were calculated theoretically [2].…”

Large resistance change on magnetic tunnel junction based molecular spintronics devices

“…However, these two approaches have been extremely difficult to mass produce robust molecular spintronics devices [5]. With conventional approaches it is also almost impossible to conduct extensive magnetic studies to explore the true effect of molecules on the magnetic properties of the molecular spintronics devices [6]. To date most of the experimental studies have only focused on the transport studies-no direct magnetic measurements were performed [3,4,7].…”

“…To date most of the experimental studies have only focused on the transport studies-no direct magnetic measurements were performed [3,4,7]. To overcome the limitations of the conventional molecular spintronics devices magnetic tunnel junctions (MTJ), produced by sandwiching an insulator between two ferromagnetic electrodes, were utilized as the test bed [5,6,8]. Under this approach an MTJ with the exposed side edges can enables the covalent bonding of desired molecular channels onto the two ferromagnetic electrodes along the junction perimeter [5].…”

Monte Carlo and Experimental Magnetic Studies of Molecular Spintronics Devices

“…3,4 Molecular channels with a net spin state are the basis of a large number of intriguing studies, 5 which were either observed experimentally 6,7 or were calculated theoretically. 2 Porphyrins, 8 single molecular magnets 2 and magnetic molecular clusters 9 possess a net spin state and can be synthetically tailored to be employed in a MSD.…”