Research Projects

Altermagnetism is a recently discovered form of magnetic order that combines features of collinear antiferromagnetism and spin polarization, without involving conventional spin- symmetric electronic states. It breaks time-reversal symmetry while maintaining zero net magnetization, thereby enabling spin-polarized transport without external magnetic fields [1,2]. This exotic order opens new possibilities for spintronic applications, including robust spin- current generation and dissipationless transport. However, only a few candidate materials are known, and the mechanisms underlying the emergence of altermagnetism remain incompletely understood. Transition metal dichalcogenides (TMDCs) are van der Waals bonded layered materials whose intercalation physics can dramatically modify both electronic and magnetic properties [3]. In this proposal, we will explore the origin of altermagnetism in layered TMDCs through controlled intercalation of 3d transition metal ions (Fe, Co, Mn). We hypothesize that introducing these magnetic ions as intercalants or dopants breaks inversion and time-reversal symmetries in a manner that stabilizes an altermagnetic state. Indeed, altermagnetism has recently been observed in Co₁/₄NbSe2 [4]. We will synthesize TMDCs crystals via chemical vapor transport (CVT) and flux zone method, then perform intercalation using an electrolyte–counter-electrode setup to achieve precise control over ion concentration. Structural and chemical analyses X-ray diffraction (XRD), X-Ray Photoelectron spectroscopy (XPS), and TEM/EDX will confirm lattice modifications, while magnetic characterization via Tempeature and Magnetic field dependent Magnetic Force Microscopy(MFM) and SQUID/VSM magnetometry will probe the ordering. Electron transport measurements under applied magnetic fields using PPMS will be employed to identify altermagnetic signatures and exotic properties in the material, while Scanning Tunneling Spectroscopy (STS) will be used to measure the local density of states (LDOS). By systematically varying intercalant species, concentration, and layer number, we aim to develop a comprehensive understanding of how intercalation controls electronic structure and magnetic symmetry. Expected outcomes includes design rules for intercalation-induced altermagnetism, phase diagrams correlating ion concentration with magnetic order, and prototype spintronic device concepts based on altermagnetic TMDCs. This interdisciplinary approach will advance fundamental knowledge and open pathways to low-dissipation magnetic technologies. References 1. Smejkal, L. et al. Altermagnetism: A New Magnetic Order. Phys. Rev. X 12, 040501. 2. Baltz, V. et al. Antiferromagnetic spintronics. Rev. Mod. Phys. 90, 015005 (2018). 3. Mian Li. et al. Chemical Intercalation of Layered Materials: From Structure Tailoring to Applications Adv. Mater. 2024, 36, 2312918. 4. J. N. Graham. et al. Local probe evidence supporting altermagnetism in Co 1/4 NbSe2. arXiv:2503.09193v1.