Magnetic excitations in CeNiC₂

CeNiC₂, which shows a heavy fermion behavior, exhibits successive magnetic transitions from paramagnetic phase to an incommensurate antiferromagnetic phase to a collinear antiferromagnetic phase with decreasing temperature at ambient pressure. With applied pressure, the long-range magnetic ordering disappears around 11 GPa and superconductivity appears with the highest superconducting transition temperature of 3.7 K [1]. Although it is challenging to study the magnetic excitations under high pressures, it is still worth studying the magnetic excitations at ambient pressure in order to determine the exchange interactions which cause the successive magnetic transitions. Inelastic neutron scattering measurements have been performed using single crystals, which have become available recently [2]. Despite the three-dimensional crystal structure, the magnetic interactions are found to be more like quasi-one-dimensional.

[1] S. Katano et al., Phys. Rev. B 99, 100501 (2019); [2] H. Ma et al., Phys. Rev. B 108, 064435 (2023).