Abstract
We considered the effect of optical pumping at the f-f transitions frequency on d-f superexchange in the rare-earth antiferromagnetic ferroborate Nd0.5Gd0.5Fe3(BO3)4 between Nd3+ ions in the excited states of the 4G5/2, 2G7/2, and Fe3+ in the ground state 6A1. In the ferroborate, d-f superexchange is directly related to the strong magnetoelectric coupling observed in the ground state of the material. We show that under optical pumping at the frequency of f-f transitions 4I9/2↔(4G5/2+2G7/2) in the Nd3+ ion, the nature of the d-f interaction changes to FM. The phenomena can be explained by the occupation of the excited Nd3+ "spin pure"states with spin 1/2, or their mixing to the optically excited states with spin 3/2 due to the spin-orbit interaction. Near optically excited ions Nd3+, magnetic frustrations change from FM ordering under the d-f AFM interaction to AFM ordering under the FM interaction in the basal hexagonal plane.
| Original language | English |
|---|---|
| Article number | 064445 |
| Journal | Physical Review B |
| Volume | 104 |
| Issue number | 6 |
| DOIs | |
| State | Published - 1 Aug 2021 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2021 American Physical Society.
Funding
The reported study was supported by the RFBR Grant 19-02-00034. V.A.G. is also grateful to the Russian Foundation for Basic Research, Government of Krasnoyarsk Territory, and Krasnoyarsk Regional Fund of Science according to the research project “Studies of superexchange and electron-phonon interactions in correlated systems as a basis for searching for promising functional materials” No. 20-42-240016.
| Funders | Funder number |
|---|---|
| Russian Foundation for Basic Research | 19-02-00034, 20-42-240016 |