Tricritical behavior of the two-dimensional intrinsically ferromagnetic semiconductor CrGeTe3

Subjects: Physics >> Condensed Matter: Electronic Structure, Electrical, Magnetic, and Optical Properties submitted time 2017-10-27

Lin, Gaoting

Abstract： CrGeTe3 recently emerges as a new two-dimensional (2D) ferromagnetic semiconductor that is promising for spintronic device applications. Unlike CrSiTe3 whose magnetism can be understood using the 2D-Ising model, CrGeTe3 exhibits a smaller van der Waals gap and larger cleavage energy, which could lead to a transition of magnetic mechanism from 2D to 3D. To confirm this speculation, we investigate the critical behavior of CrGeTe3 around the second-order paramagnetic-ferromagnetic phase transition.We obtain the critical exponents estimated by several common experimental techniques including the modified Arrott plot, Kouvel-Fishermethod, and critical isotherm analysis, which show that themagnetism of CrGeTe3 follows the tricritical mean-field model with the critical exponents β, γ , and δ of 0.240 ± 0.006, 1.000 ± 0.005, and 5.070 ± 0.006, respectively, at the Curie temperature of 67.9 K.We therefore suggest that the magnetic phase transition from 2D to 3D for CrGeTe3 should locate near a tricritical point. Our experiment provides a direct demonstration of the applicability of the tricritical mean-field model to a 2D ferromagnetic semiconductor.

Peer Review Status:Awaiting Review

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