Ising-type Magnetic Ordering in few-layer FePS$_{3}$

Magnetic ordering in two-dimensional materials is important both in fundamental science and application. However, two-dimensional material with intrinsic magnetism has not been investigated much. We present the observation of intrinsic antiferromagnetic ordering in the two-dimensional limit. Transition metal phosphorus trisulfides (MPS3) are a new class of layered materials. Some of the bulk MPS$_{3}$ materials (FePS$_{3}$, MnPS$_{3}$ and NiPS$_{3})$ exhibit antiferromagnetic phase transitions at low temperature. By using mechanical exfoliation, we prepared mono- and few-layer FePS$_{3}$ samples. We monitored the Raman peaks that arise from zone folding due to antiferromagnetic ordering below the transition temperature. We observed an Ising-type antiferromagnetic ordering in FePS$_{3}$ down to the mono-layer. The transition temperature is almost independent of the thickness from bulk to the monolayer with \textasciitilde 118 K. This implies that the interlayer interaction has little effect on the antiferromagnetic ordering in few-layer FePS$_{3}$.