Survey of the Thermodynamic Properties of the Charge Density Wave Systems

Figure 4

Color on line. Experimental discontinuities (absolute values) of the velocity of the longitudinal C₁₁ and C₃₃ shown as a function of T_CDW (Tables 1 and 2). Results obtained with TbTe₃ (blue circle T_CDW = 330 K) [41], ErTe₃ (black circles T_CDW1 = 260 K and T_CDW2 = 155 K) [42], and HoTe₃ (brown circles T_CDW1 = 280 K and T_CDW2 = 120 K) [43]. Results obtained by Young and velocity measurements NbSe₃ (green circle) [27], 2H-NbSe₂ (blue squares) [16, 17], TiSe₂ (violet circle) [20], 2H-TaSe₂ (red down triangle) [16], K_0.3MoO₃ (blue up triangle [31]), (TaSe₄)₂I (brown diamond) [39], TTF-TCNQ (black diamonds) with a large discrepancy (~0.0001, 0.01 shown by the dotted black line [36, 37]), and Cr (light blue [54]).