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Antiferromagnetic (AFM) materials have zero net magnetic moments due to the alignment of adjacent magnetic moments antiparallel to each other, which have drawn extensive interest in the field of next generation spintronics, thanks to the merits of negligible stray fields, fast spin dynamics, and robustness against magnetic disturbances. In the past decades, the strongly correlated vanadates of VO2, V2O3, and RVO3 have extensively been studied because of noteworthy metal–insulator transitions. Nevertheless, the magnetism (especially antiferromagnetism) in the vanadates has attracted less attention. This Perspective provides a brief overview of the strongly correlated AFM vanadates. First, an introduction to the basic concept of antiferromagnetism and vanadates is presented. Then, the antiferromagnetism in vanadates containing V4+ (VO2, NaV2O5, and Sr2VO4), V3+ (V2O3, RVO3, AV2O4, and VOCl), and V2+ (VO) with different spin moments is presented. Finally, a summary and outlook with respect to the antiferromagnetism in vanadates are included.

Magnetic topological materials have attracted significant attention due to their potential realization of a variety of novel quantum phenomena. EuIn_{2}As_{2} has recently been theoretically recognized as a long-awaited intrinsic antiferromagnetic bulk axion insulator. However, experimental studies of the transport properties arising from the topological states in this material are scarce. In this paper, we perform detailed magnetoresistance (MR) and Hall measurements to study the magnetotransport properties of this material. We find that the transport is strongly influenced by the spin configuration of the Eu moments from the concomitant change in the field dependence of the MR and that of the magnetization below the Néel temperature. Most importantly, an anomalous Hall effect (AHE) and a large topological Hall effect (THE) are observed. We suggest that the AHE is originated from a nonvanishing net Berry curvature due to the helical spin structure and that the THE is attributed to the formation of a noncoplanar spin texture with a finite scalar spin chirality induced by the external magnetic field in EuIn_{2}As_{2}. Our studies provide a platform to understand the influence of the interplay between the topology of electronic bands and the field-induced magnetic structure on magnetoelectric transport properties. In addition, our observations give a hint to realize axion insulator states and higher-order topological insulator states through manipulating the magnetic state of EuIn_{2}As_{2}.

M-type strontium hexaferrites of Sr1−xLaxFe12−xMnxO19 (0.0≤x≤0.4) were synthesized by the chemical coprecipitation method. X-ray diffraction (XRD) studies indicate that the samples are single-phase with the space group of P63/mmc. The results of field-emission scanning electronic microscopy (FE-SEM) show that the grains are regular hexagonal platelets with sizes from 0.7 to 1.4 μm. It is observed that the value of Hc increases at low substitution (x ≤ 0.1), reaches a maximum at x = 0.1 and then decreases at x ≥ 0.1, while the value of Ms decreases monotonously with increasing x. The variations of magnetic properties can be tentatively attributed to the effects of La–Mn substitutions. The results above indicate that our samples might be promising candidates for permanent magnets in the future.

We present a study of phase escape in surface Bi _2 Sr _2 CaCu _2 O _8+ _δ intrinsic Josephson junctions in the presence of microwave radiation. The measured switching current distributions display clear double-peak structures in the microwave field, which result from the single- and two-photon resonant escape processes accompanied by microwave-induced potential barrier suppression. We show that these results can be well explained by a quantum-mechanical model proposed by Fistul et al (2003 Phys. Rev. B 68 060504), from which the power and frequency dependences of the switching current distributions can be reproduced.