Spin-induced negative thermal expansion and spin–phonon coupling in van der Waals material CrBr3

• Published in: npj quantum materials Vol. 6; no. 1; pp. 1 - 5
• Main Authors: Kozlenko, D. P., Lis, O. N., Kichanov, S. E., Lukin, E. V., Belozerova, N. M., Savenko, B. N.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.03.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119/2793; 639/301/119/997; Chromium bromides; Condensed Matter Physics; Coupling; Curie temperature; Ferromagnetic materials; Lattice parameters; Lattice vibration; Magnets; Nanoelectronics; Nanotechnology devices; Phonons; Physics; Physics and Astronomy; Quantum Physics; Raman spectroscopy; Spintronics; Structural Materials; Surfaces and Interfaces; Thermal expansion; Thin Films
• ISSN: 2397-4648; 2397-4648
• DOI: 10.1038/s41535-021-00318-5

The two-dimensional van der Waals (vdW) magnets retaining magnetic order in atomically thin limit demonstrate challenging physical phenomena and they are considered as prospective building blocks for construction of advanced spintronics and nanoelectronics devices. Here, we present experimental evidence for negative thermal expansion of lattice volume and vdW layers and strong spin–phonon coupling effects, caused by formation of the long-range ferromagnetic order in the vdW material CrBr 3 . The neutron and X-ray diffraction measurements revealed anomalous temperature variation of lattice parameters and interatomic distances and angles in the vicinity of Curie temperature ( T C ). A pronounced rise of the frequencies of the most of the observed vibrational modes and unusual reversal broadening of their full widths at half maximum below T C was found from Raman spectroscopy measurements.