Elastic anomalies at the charge density wave transition in TbTe3

Survey of the Thermodynamic Properties of the Charge Density Wave Systems

“…The temperature dependence of the sound velocity and the amplitude of the superlattice reflections gives directly the temperature dependence of the order parameter [1]. This general behavior has been observed at the CDW phase transition T CDW in different materials [16,17,20,36,37,[41][42][43]. The hardening observed in the ordered phase with several compounds is analyzed in Section 3.5.…”

“…The contribution of the fluctuations is important in the quasione-dimensional conductors [28] and in the transition metal dichalcogenides (2H-TaSe 2 , 2H-TaS 2 ) [24]. Small fluctuation effects are observed around T CDW in the rare earth tritellurides TbTe 3 [41] and ErTe 3 [42].…”

“…(a) Rare earth tritellurides TbTe 3 [41] and ErTe 3 [42] (b) Transition metal dichalcogenides 2H-NbSe 2 [19] [44] and Cr [53] The specific heat discontinuities ûC P are reported in Tables 1-4 and they are shown as a function of the CDW phase transition temperature T CDW in Figure 2. A linear dependence is expected û = .…”

“…Heat specific discontinuities ûC P at the CDW phase transition T CDW (Table 1) as a function of T CDW . TbTe 3 (blue circle) [41]; ErTe 3 (black circles T CDW1 = 260 K, T CDW2 = 155 K) [42]; TiSe 2 (violet circles, T CDW =200 K with two different results given in [22,23]); LaAgSb 2 (red square T CDW1 = 210 K) [44]; NbSe 3 (green circle T CDW1 = 145 K, T CDW2 = 48 K) [26]; 2H-NbSe 2 (blue squares T CDW = 30 K) [19]; 2H-TaSe 2 (red down triangle T CDW =120 K) and 2H-TaS 2 (red up triangles T CDW = 80 K) mean field contribution given by [24]; TTF-TCNQ (black diamond symbol mean field contribution given in [35]); K 0.3 MoO 3 (blue up triangles T CDW = 180 K) two different results given by [30]; (TaSe 4 ) 2 I (brown diamond T CDW = 260 K [40]); Cr (light blue square [53]). Lines (1) and (2) are lineal temperature dependence.…”

“…(Tables 1 and 2). Results obtained with TbTe 3 (blue circle T CDW = 330 K) [41], ErTe 3 (black circles T CDW1 = 260 K and T CDW2 = 155 K) [42], and HoTe 3 (brown circles T CDW1 = 280 K and T CDW2 = 120 K) [43]. Results obtained by Young and velocity measurements NbSe 3 (green circle) [27], 2H-NbSe 2 (blue squares) [16,17], TiSe 2 (violet circle) [20], 2H-TaSe 2 (red down triangle) [16], K 0.3 MoO 3 (blue up triangle [31]), (TaSe 4 ) 2 I (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]).…”