Year: 2023
Type: article
Abstract: Mixed halide chemistry has recently been utilized to tune the intrinsic magnetic properties of transition-metal halides---one of the largest families of magnetic van der Waals materials. Prior studies have shown that the strength of exchange interactions, hence the critical temperature, can be tuned smoothly with halide composition for a given ground state. Here we show that the ground state itself can be altered by a small change of halide composition in ${\mathrm{FeCl}}_{3\ensuremath{-}x}{\mathrm{Br}}_{x}$. Specifically, we find a threefold jump in the N\'eel temperature and a sign change in the Weiss temperature at $x=0.08$ corresponding to only $3%$ bromine doping. Using neutron scattering, we reveal a change of the ground state from spiral order in ${\mathrm{FeCl}}_{3}$ to $A$-type antiferromagnetic order in ${\mathrm{FeBr}}_{3}$. From first-principles calculations, we show that a delicate balance between nearest and next-nearest neighbor interactions is responsible for such a transition. These results demonstrate how varying the halide composition can tune the competing interactions and change the ground state of a spiral spin liquid system.
Source: Physical Review Materials
Institutions: Boston College, Aalto University, Oak Ridge National Laboratory
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: G1019100964, G121915436, G1528409558, G1645119126, G1919324638, G203625172, G2310544143, G2411683797, G2988778103, G3049477530, G4423657506, G5046801523, G5172861670, G6486853205, G675320460, MULTI-VAN: Designing new Multiferroics with layered van der Waals materials, G6911681599, CAS: Using Narrow Bands and Competing Exchange Interactions as Design Principles for Magnetocaloric Materials, Engineering fractional quantum matter in twisted van der Waals materials, G807938293, G8269158468, G8906985441, G992184245
OpenAlex ID: W4379162271