Abstract
We studied magnetic properties in the TbNi2Si2 single crystal compound by magnetic and neutron diffraction measurements. The magnetic moments born on only Tb are fixed to the c-axis due to a strong crystalline electric effect. The compound undergoes a commensurate-incommensurate phase transition at Tt=7.9 K; the commensurate phase with k=[1⁄2, 1⁄2, 0] is stable below Tt, and above Tt, the incommensurate one with k=[1⁄2+τ, 1⁄2−τ, 0] (τ=0.074) appears and persists up to TN=14.6 K. A multi-step metamagnetic transition was found in the low temperature c-axis magnetization process in which at least nine magnetic phases appear. This process is a typical example of “the devil’s staircase” in real compounds.
