Magnetic properties of a few layered NiPS₃

Shivani Sharma^1*, Danru Qu², Ren-hao Jhang¹, Li-Zai Tsai¹, Bo Chein Huang¹, Raman Sankar¹, Shang Fan Lee¹

¹Institute of Physics, Academia Sinica, Taipei, Taiwan, Taiwan
²Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan

* Presenter:Shivani Sharma, email:shivanisharma18@gate.sinica.edu.tw

Recently, 2D materials have gained significant attention due to their exotic physical properties in the 2D limit. Transition metal phosphorus trisulfides (XPS3, X= V, Mn, Fe, Co, Ni, or Zn) are a new class of antiferromagnetic van der Waals materials, allowing one to examine the dependence of the magnetic ordering on the dimensionality [1,2]. Among these, NiPS₃ is a layered insulating antiferromagnetic van der Waals crystal with a Neel transition temperature of approximately 170 K in its bulk form [3]. The magnetic order of NiPS₃ is described by the highly anisotropic XXZ Heisenberg model, upon thinning of the film, magnetic fluctuations are found to dominate and magnetic ordering is dramatically suppressed in the monolayer limit [4].

In the present work, we report the magnetic properties of a few-layer NiPS₃. Samples were prepared by the micromechanical exfoliation method. SQUID measurements have revealed a Neel temperature of 125 K. The Raman spectra revealed various Raman active modes at 377, 276, 242 cm-1 corresponding to A²₁g, E⁴g, A¹₁g modes. Interestingly, mode position changes with the number of layers, a typical feature useful in quantifying the number of layers from Raman data. Further, the magnetization switching of the NiPS₃ moment is expected by electric means. Electric-field-controlled magnetism in 2D magnets will open new possibilities for potential applications in new-generation magnetic memory storage, sensors, and spintronics.



References:

[1] Wang, F. et al., Adv. Funct. Mat. 28, 1802151 (2018).

[2] Susner, M. et al., Adv. Mater. 29, 1602852 (2017).

[3] Schippers C. F. et al., Physical Review B 94, 184428 (2016).

[4] Kangwon Kim et al., NATURE COMMUNICATIONS 10, 345 (2019).

Keywords: 2D materials, antiferromagnetic , magnetization switching, NiPS3, Heisenberg model