Dynamic magnetic crossover at the origin of the hidden-order in van der Waals antiferromagnet CrSBr

• Published in: Nature communications Vol. 13; no. 1; p. 4745
• Main Authors: López-Paz, Sara A., Guguchia, Zurab, Pomjakushin, Vladimir Y., Witteveen, Catherine, Cervellino, Antonio, Luetkens, Hubertus, Casati, Nicola, Morpurgo, Alberto F., von Rohr, Fabian O.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12-08-2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119/997; 639/301/357/1018; Anisotropy; Antiferromagnetism; Critical temperature; Crystal structure; Electrical properties; Ferromagnetism; Freezing; Humanities and Social Sciences; Low temperature; Magnetic materials; Magnetic properties; Magnetic variations; Mixed anions; multidisciplinary; Phase transitions; Science; Science (multidisciplinary); Spintronics; Temperature
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-32290-4

The van-der-Waals material CrSBr stands out as a promising two-dimensional magnet. Here, we report on its detailed magnetic and structural characteristics. We evidence that it undergoes a transition to an A-type antiferromagnetic state below
T
N
 ≈ 140 K with a pronounced two-dimensional character, preceded by ferromagnetic correlations within the monolayers. Furthermore, we unravel the low-temperature hidden-order within the long-range magnetically-ordered state. We find that it is associated to a slowing down of the magnetic fluctuations, accompanied by a continuous reorientation of the internal field. These take place upon cooling below
T
s
 ≈ 100 K, until a spin freezing process occurs at
T
* ≈ 40 K. We argue this complex behavior to reflect a crossover driven by the in-plane uniaxial anisotropy, which is ultimately caused by its mixed-anion character. Our findings reinforce CrSBr as an important candidate for devices in the emergent field of two-dimensional magnetic materials.
A 2D magnet CrSBr has attracted interest for applications in spintronics due to its high critical temperature and interesting magneto-electrical properties. Here the authors report a detailed study of its magnetic and structural phases and uncover a hidden magnetic order inside the magnetically-ordered phase.