In the Search for Magnetic Skyrmions: An Experimental and Computational Approach Towards the Synthesis and Characterization of Mn1-XFexp

In comparison to traditional electronics, which exclusively utilizes charge, spintronic devices utilize both charge and spin. One avenue towards the design of spintronic devices is through materials that can host magnetic skyrmions.

My research focuses on exploring suitable materials that can host magnetic skyrmions, which are quasiparticles that consists of a localized whirl of spins in a magnetic material. There are multiple types of magnetic skyrmions, a common example being the Néel-type, where the spins rotate from pointing downward at the center of the skyrmion to upward at the edge of the skyrmion, forming a spin texture. Magnetic skyrmions have applications for both memory storage and quantum computing. For a material to host magnetic skyrmions, it should have broken inversion symmetry and spin-orbit coupling (SOC) that can induce an asymmetric (Dzyaloshinskii-Moryia) exchange interaction. The Mn_1-xFe_xP series satisfies such criteria. For magnetic skyrmions to be utilized in spintronic applications, individual skyrmions should be stable close to room temperature and at very small or zero applied field. The Mn_1-xFe_xP series could host magnetic skyrmions due to MnP and FeP having high transition temperatures in comparison to most known magnetic materials, which is ideal for spintronic applications.

The synthesis of the series has been successfully performed in polycrystalline form, in which it was made through conventional solid-state synthesis methods. Chemical Vapor Transport (CVT) reactions were attempted in synthesizing single crystals of the series, that resulted in unsuccessful results. A computational approach towards modelling these reactions is performed in order to provide insight into the optimal conditions in which the series can be grown. The structure, composition, and the magnetic properties of the polycrystalline series has been characterized and measured.

From the currently measured data, Mn_0.7Fe_0.3P appears to have the most promising attributes for skyrmion formation. Several compositions exhibit spin canting at lower temperatures, as well as competing ferromagnetic and antiferromagnetic exchange interactions. Computational modeling of iodine adsorption on the three most common facets of MnP suggests that such strong adsorption onto Mn atoms in each slab complicates single crystal growth by the CVT method when iodine is used as the transport agent.