Compressive strain induced enhancement of exchange interaction and short-range magnetic order in investigated by Raman spectroscopy
Physical Review B, 2019•APS
We have carried out Raman spectroscopy experiments to investigate two-magnon
excitations in epitaxial thin films of the quasi-two-dimensional antiferromagnetic Mott
insulator S r 2 Ir O 4 under in-plane misfit strain. With in-plane biaxial compression, the
energy of the two-magnon peak increases and the peak remains observable over a wider
temperature range above the Néel temperature, indicating a strain-induced enhancement of
the superexchange interactions between J eff= 1/2 pseudospins. From density functional …
excitations in epitaxial thin films of the quasi-two-dimensional antiferromagnetic Mott
insulator S r 2 Ir O 4 under in-plane misfit strain. With in-plane biaxial compression, the
energy of the two-magnon peak increases and the peak remains observable over a wider
temperature range above the Néel temperature, indicating a strain-induced enhancement of
the superexchange interactions between J eff= 1/2 pseudospins. From density functional …
We have carried out Raman spectroscopy experiments to investigate two-magnon excitations in epitaxial thin films of the quasi-two-dimensional antiferromagnetic Mott insulator under in-plane misfit strain. With in-plane biaxial compression, the energy of the two-magnon peak increases and the peak remains observable over a wider temperature range above the Néel temperature, indicating a strain-induced enhancement of the superexchange interactions between pseudospins. From density functional theory calculations, we have found an increase of the nearest-neighbor hopping parameter and exchange interaction with increasing biaxial compressive strain, in agreement with the experimental observations. Our experimental and theoretical results provide perspectives for systematic, theory-guided strain control of the primary exchange interactions in transition-metal oxides.