2017/06/10 by Gaoting Lin, G. T. Lin, H. L. Zhuang +24
Materials Science · Physics and Astronomy · #2D Materials and Applications #Condensed matter physics #Critical exponent #Curie temperature #Ferromagnetism #Ising model #Magnetic semiconductor #Magnetism #Paramagnetism #Phase (matter) #Phase diagram #Phase transition #Physics #Quantum many-body systems #Quantum mechanics #Theoretical and Computational Physics #Tricritical point #cond-mat.mtrl-sci #cond-mat.str-el #van der Waals force
paper · pdf · doi:10.1103/physrevb.95.245212
Accepted by Phys. Rev. B
arxiv created 2017/06/10 · openalex created_date 2017/06/23 · openalex publication_date 2017/06/30 · arxiv updated 2017/08/02 · openalex updated_date 2026/08/05
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-Fisher method, and critical isotherm analysis, which show that the magnetism of CrGeTe3 follows the tricritical mean-field model with the critical exponents \ensuremathβ, \ensuremathγ, and \ensuremathδ of 0.240\ifmmode±\else\textpm\fi0.006, 1.000\ifmmode±\else\textpm\fi0.005, and 5.070\ifmmode±\else\textpm\fi0.006, 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.