Vibrational properties of SrVO2 H with large spin-phonon coupling
Artikel i vetenskaplig tidskrift, 2022

The antiferromagnetic transition metal oxyhydride SrVO2H is distinguished by its stoichiometric composition and an ordered arrangement of H atoms. The tetragonal structure is related to the cubic perovskite and consists of alternating layers of VO2 and SrH. d2 V(III) attains a sixfold coordination by four O and two H atoms. The latter are arranged in a trans fashion, which produces H-V-H chains along the tetragonal axis. Here, we investigate the vibrational properties of SrVO2H by inelastic neutron scattering and infrared spectroscopy combined with phonon calculations based on density functional theory. The H-based vibrational modes divide into a degenerate bending motion perpendicular to the H-V-H chain direction and a highly dispersed stretching motion along the H-V-H chain direction. The bending motion, with a vibrational frequency of approximately 800 cm-1, is split into two components separated by about 50 cm-1, owing to the doubled unit cell from the antiferromagnetic structure. Interestingly, spin-phonon coupling stiffens the H-based modes by 50-100cm-1 although super-exchange coupling via H is very small. Frequency shifts of the same order of magnitude also occur for V-O modes. It is inferred that SrVO2H displays the hitherto largest recognized coupling between magnetism and phonons in a material.


Rasmus Lavén

Chalmers, Kemi och kemiteknik, Energi och material

Pedro Ivo R. Moraes

Universidade Federal de Juiz de Fora

Michael Sannemo Targama

Stockholms universitet

Maths Karlsson

Chalmers, Kemi och kemiteknik, Energi och material

Alexandre A. Leitão

Universidade Federal de Juiz de Fora

Paulo H.B. Brant Carvalho

Stockholms universitet

Stewart F. Parker

STFC Rutherford Appleton Laboratory

Ulrich Häussermann

Stockholms universitet

Olga Yu Vekilova

Stockholms universitet

Physical Review Materials

24759953 (eISSN)

Vol. 6 2 024409



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