Electrical Behavior of Thin Film Devices Exposed to a Magnetic Field

The exploration of novel, magnetically controlled thin film devices can enable a range of technologies. For example, we demonstrated that the incorporation of ferromagnetic materials into a diode-type device can enable changes in electrical behavior in the presence of a weak, permanent magnet.[1] The diode, when combined with an antenna array, could serve as a rectification device. Magnetic control of the rectenna was referred to as mem(ory)rectification, which would not increase the electrical burden given that the permanent magnet did not require an external power source. Another application is the generation or storage of code in a series of magnetic thin film devices. An applied magnetic field could write or erase an electrical message that is stored in the thin film devices. The materials properties of an array of devices could be varied to store a code that could be decrypted or erased via the application of a magnetic field.<br/><br/>Moving forward, the study of the device behavior in a stronger magnetic field in different configurations with respect to the direction of the applied field (in-plane vs. out-of-plane) would enable a better understanding of how the magnetic field influences the average electronic motion through the device. We will use a dipole electromagnet with adjustable pole gap and coil spacing to apply the field, which can be at least 1T, depending on the pole gap spacing. This builds upon our previous work in which the relatively weak magnetic field (~690 Oe) was roughly perpendicular to the film stack and therefore roughly parallel to the electronic transport across the layers. For this MRS presentation, we will measure and understand the transport when the magnetic field lies roughly in the plane of the sample, roughly perpendicular to the electronic flow between layers in the Metal-Insulator-Metal (MIM) diode stack. We will also report the impact of the fabrication techniques on device quality and performance. Dielectric layer (niobium oxide (NbOx)) deposition using atomic layer deposition (ALD) can enable single layer deposition and the deposition of a few layers. Preliminary characterization of the ALD-deposited NbOx using x-ray photon spectroscopy (XPS) revealed that the deposited layer was in the Nb₂O₅ oxidation state, with peaks found at 208.4 eV and atomic percentages of 29% niobium and 71% oxygen.<br/><br/>[1] Strack, G., Kim, J.H., Giardini, S. Akyurtlu, A, and Osgood, R. III Application of a magnetic field to ferromagnetic diodes. <i>MRS Advances</i> (2023). https://doi.org/10.1557/s43580-023-00520-6