Magnetic anisotropy, magnetization reversal and switching in NiNbOsingle crystals.

NiNbOis an insulating compensated ferrimagnet with= 77 K and= 33 K. We report here the study of the magnetic anisotropy using millimeter-size crystals grown in an image furnace. The magnetization measurements, vs temperature, performed withaligned along the three main crystallographic axes, show similar Curie-Weiss temperatures (≈ 190 K) and rather similar effective paramagnetic moments (from 3.5to 3.6). This suggests that the strongest magnetic interaction is the antiferromagnetic one, coupling the ferromagnetic distorted honeycomb layers and zigzag ribbons via face sharing NiOoctahedra. This strong antiferromagnetic coupling is supported by DFT calculations that do not evidence any inter site ferromagnetic interaction, leading to total compensation between magnetic moments of both Nisites. Measurements vs magnetic field belowreveal an anisotropic behaviour, with square magnetization loops forin theplane, whereas linear() curves without hysteresis are observed for. This anisotropy betweenplane andaxis occurs also in the magnetization reversal (MR), which is observed in theplane only. Starting from() virgin curves collected just below= 33 K withor, the memory-like effect was tested through magnetization switching induced byoralternating changes. Below, smalleris needed to switchsymmetrically foralongthan along, and, forswitching (2 K interval, constant), a largerchange is obtained alongthan along. The comparison with ferrimagnetic oxides which exhibit MR, like spinels or rare earth orthoferrites, shows that NiNbOis unique since only one magnetic cation over two sites in octahedral coordination is at play, thus providing a unique platform to studyswitching but also a challenge for theoretical interpretation.