A1 Journal article (refereed)
Substituent effects on exchange anisotropy in single- and multiorbital organic radical magnets (2024)


Marbey, J., Mailman, A., Oakley, R., Hill, S., & Winter, S. (2024). Substituent effects on exchange anisotropy in single- and multiorbital organic radical magnets. Physical Review Materials, 8(4), Article 044406. https://doi.org/10.1103/PhysRevMaterials.8.044406


JYU authors or editors


Publication details

All authors or editorsMarbey, Jonathan; Mailman, Aaron; Oakley, Richard, T.; Hill, Stephen; Winter, Stephen, M.

Journal or seriesPhysical Review Materials

ISSN2476-0455

eISSN2475-9953

Publication year2024

Publication date19/04/2024

Volume8

Issue number4

Article number044406

PublisherAmerican Physical Society (APS)

Publication countryUnited States

Publication languageEnglish

DOIhttps://doi.org/10.1103/PhysRevMaterials.8.044406

Publication open accessNot open

Publication channel open access

Publication is parallel published (JYX)https://jyx.jyu.fi/handle/123456789/94842


Abstract

The contribution of heavy-atom substituents to the overall spin-orbit interaction in two classes of organic radical molecular magnets is discussed. In “single-orbital” radicals, spin-orbit coupling (SOC) effects are well described with reference to pairwise anisotropic exchange interactions between singly occupied spin-bearing orbitals on neighboring molecules; anisotropy requires the presence of spin density on heavy-atom sites with principal quantum number n > 3. In “multiorbital” radicals, SOC involving virtual orbitals also contributes to anisotropic exchange and, as a result, the presence of heavy (n > 3) atoms in formally non-spin-bearing sites can enhance pseudodipolar ferromagnetic interaction terms. To demonstrate these effects, ferromagnetic and antiferromagnetic resonance spectroscopies have been used to probe the exchange anisotropy in two organic magnets, one a “single-orbital” ferromagnet, the other a “multiorbital” spin-canted antiferromagnet, both of which contain a heavy-atom iodine (n = 5) substituent. While the symmetry of the singly occupied molecular orbital in both radicals precludes spin-orbit contributions from iodine to the overall exchange anisotropy, the symmetry and energetically low-lying nature of the lowest unoccupied molecular orbital in the latter allows for appreciable spin density at the site of iodine substitution and, hence, a large exchange anisotropy.


Keywordsheterocyclic compoundsfree radicalscrystalsmagnetic propertiesmolecular physics

Free keywordsmagnetic anisotropy; magnetic interactions; magnetic order; molecular magnetism; spin-orbit coupling techniques; density functional theory; electron spin resonance; ferromagnetic resonance


Contributing organizations


Ministry reportingYes

Reporting Year2024

Preliminary JUFO rating2


Last updated on 2024-15-05 at 11:41