Scaling of the magnetic entropy change in chiral helimagnetic YbNi3Al9

Abstract

Generally, magnetic anisotropy is a common feature of a layered magnetic material, the exploration of which plays a key role in understanding the intrinsic magnetic couplings. In this work, we have studied the field-induced magnetic transitions for layered YbNi3Al9 as the external magnetic field is applied perpendicularly () and parallel (H//c) to the c-axis. We find that two independent universal curves of magnetic entropy change [] can be fitted out for and H//c, respectively. According to the universality principle of scaling, the extra magnetic entropy changes ( and ) caused by the field-induced magnetic phase transitions can be obtained for and H//c. The two-dimensional plots as functions of field and temperature are constructed, which clearly reveal the evolutions of the magnetic entropy changes resulted from the two different field-induced magnetic phase transitions. It is suggested that the for with the maximum at (3.2 K, 4.1 kOe) originates from a field-modulated helicoidal spin-texture. However, the for H//c with the maximum at (3.4 K, 13.8 kOe) stems from a field-induced canted antiferromagnetic state.