Fig. 1: Structure and magnetic properties of antiferromagnetic CrPS₄.

a Crystallographic structure of CrPS₄, viewed from a axis. Cr³⁺ ions composed of CrS₆ octahedra form quasi-1D chains along the b axis. The red arrow on each Cr³⁺ ion corresponds to the individual spin direction, displaying A-type antiferromagnetic order. The large red arrow adjacent to a layer represents net magnetic moments alternately repeating along the c axis. b Structure viewed from c axis. The green, purple, and yellow spheres represent the Cr³⁺, P⁵⁺, and S^2- ions, respectively. The dotted rectangle denotes crystallographic unit cell. c Dark-field images collected by scanning transmission electron microscopy (STEM) in the ac plane. STEM image with lower magnification illustrates the regular alignment of all layers. d Temperature (T) dependence of the magnetic susceptibility for H//c (χ_c) and H//b (χ_b), measured at H = 0.1 T. The vertical dotted gray line indicates the Néel T, T_N = 38 K. e Solid curve of the isothermal magnetization for H//c (M_c), measured at T = 2 K. Calculated M_c is plotted as the dotted curve. The red inverted triangle marks occurrence of spin-flop transition, H_flop = 0.9 T. The inset shows a magnified view of M_c around H_flop. The dotted gray line is extrapolated from the linear slope above H_flop. The schematics illustrate the angular variation of the Cr³⁺ magnetic moments in the consecutive layers upon increasing H along the c axis (H_c). f Solid curve of the isothermal magnetization for H//b (M_b), measured at T = 2 K. The calculated M_b is shown as the dotted curve. the schematics illustrate gradual canting of the Cr³⁺ moments upon increasing H along the b axis (H_b).