Strain effect on magnetic-exchange-induced phonon splitting in NiO films

0532988 - FZÚ 2021 RIV GB eng J - Journal Article
Kashir, A. - Goian, Veronica - Yoon, D. - Cho, B.J. - Jeong, Y.H. - Lee, G.H. - Kamba, Stanislav
Strain effect on magnetic-exchange-induced phonon splitting in NiO films.
Journal of Physics-Condensed Matter. Roč. 32, č. 40 (2020), s. 1-8, č. článku 405607. ISSN 0953-8984. E-ISSN 1361-648X
R&D Projects: GA MŠMT(CZ) EF16_019/0000760; GA ČR GA18-09265S
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institutional support: RVO:68378271
Keywords : exchange coupling * phonons * infrared spectroscopy * thin films
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 2.333, year: 2020
Method of publishing: Limited access
https://doi.org/10.1088/1361-648X/ab9f08

NiO thin films with various strains were grown on SrTiO3 (STO) and MgO substrates using a pulsed laser deposition technique.The variation of in-plane strain from -0.36% (compressive) to 0.48% (tensile) yields the decrease of the phonon frequency from 409.6 cm-1 to 377.5 cm-1which occurs due to the ~1% change of interatomic distances. The magnetic exchange-driven phonon splitting Δω was measured as a function of temperature. The Δω increases on cooling in NiO relaxed film. The splitting increases on cooling also in 0.48% tensile strained film, but Δω is systematically 3-4 cm-1 smaller than in relaxed film. Since the phonon splitting is proportional to the non-dominant magnetic exchange interaction J1, the reduction of phonon splitting in tensile-strained film was explained by a diminishing of J1 with lattice expansion.

Permanent Link: http://hdl.handle.net/11104/0311491