Nanoscale Tantalum layer impacting magnetic properties of tunnel junction-based molecular devices
- PDF / 1,015,931 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 108 Downloads / 208 Views
esearch Letter
Nanoscale Tantalum layer impacting magnetic properties of tunnel junction-based molecular devices Pawan Tyagi, Mechanical Engineering, University of the District of Columbia, Washington DC-20008, USA; Chemical and Materials Engineering, University of Kentucky, Lexington, KY-40566, USA Tobias Goulet, Mechanical Engineering, University of the District of Columbia, Washington DC-20008, USA Address all correspondence to Pawan Tyagi at [email protected] (Received 28 April 2018; accepted 5 July 2018)
Abstract Magnetic tunnel junction can produce highly configurable molecular spintronics devices. This paper highlights a rather subtle attribute of magnetic tunnel junction fabrication that can lead to the very pronounced impact on magnetic properties of molecular spintronics device. We conducted magnetic studies to observe the effect of depositing ∼5 nm Tantalum (Ta) on the top of a magnetic tunnel junction. We investigated the effect of Ta by using characterization techniques like ferromagnetic resonance, magnetometry, and polarized neutron reflectometry. Bridging paramagnetic molecules between the two ferromagnetic electrodes of magnetic tunnel junctions with and without Ta top layer produced the very different magnetic response.
Introduction Molecular spintronics devices are considered a strong candidate for developing futuristic logic and memory devices.[1] A versatile form of molecular spintronics devices can be produced by utilizing a magnetic tunnel junction as the testbed. Utilization of a magnetic tunnel junction with the exposed side edges for enabling the bridging of molecular channels between two ferromagnetic electrodes along the junction edges offer tremendous advantages over conventional methods.[2,3] Suitability and properties of the magnetic tunnel junction test bed mainly depend on the electrode materials and the insulating spacer or tunnel barrier. Study of magnetic tunnel junction literature suggests that various insulating spacers or tunneling barrier lead to different magnetoresistance like properties.[4] Past literature also provides a vast knowledge with regard to the impact of ferromagnetic electrodes on the impact of magnetic tunnel junction properties. A few studies have suggested the impact of adding tantalum (Ta) layer on the ferromagnetic electrode.[5] Prior work suggests that deposition of Ta layer on a NiFe like a ferromagnet produced a dead layer.[6] However, prior literature provides limited insight about the impact of Ta top layer on the magnetic tunnel junction. Here we present our study focusing on the Ta impact on a magnetic tunnel junction with Ta(2 nm)/Co (5 nm)/NiFe (5 nm)/AlOx(2 nm)/NiFe (10–15 nm) configuration. Here we also discussed that Ta’s subtle impact on magnetic tunnel junction resulted in significant impact on magnetic tunnel junctionbased molecular spintronics devices.
Experimental details We produced magnetic tunnel junction pillars with the exposed side edges to transform them into molecular spintronics devices.
1024 ▪
To avoid the undesirable impact of edge
Data Loading...
