Coupling of charge and lattice degrees of freedoms in θ-type BEDT-TTF compound probed by low-temperature heat capacity measurements

Thermodynamics of the quantum spin liquid state of the single-component dimer Mott system κ−H3(Cat−EDT−TTF)2Yamashita1, Nakazawa2, Ueda3 et al. 2017Phys. Rev. BSelf Cite263251View full textAdd to dashboardCite

“…In the latters, the planer symmetric donors may have libration phonon modes and gives an additional contribution expressed by Einstein type model. [23][24][25] It is inferred that the linkage by proton or deuteron makes the inter-layer connection rigid and leads the lattice vibration to have more three dimensional character, although the lattice itself retains flexible features as is inferred from the absolute value of the β.…”

Single Crystal Heat Capacity Measurement of Charge Glass Compound θ-(BEDT-TTF)2CsZn(SCN)4 Performed under Current and Voltage Application

“…A peculiar feature was observed in the heat capacity of θ-(BEDT-TTF) 2 CsZn(SCN) 4 by Yoshimoto et al in the normal condition [20]. The temperature dependence of the lattice heat capacity divided by T 3 shows a large Boson peak structure around 2-3 K, which is a typical feature of molecular glasses and amorphous compounds [20,28,29]. On the other hand, such a peak structure is absent in the charge-ordered (CO) state of slowly cooled θ-(BEDT-TTF) 2 RbZn(SCN) 4 and metallic θ-(BEDT-TTF) 2 I 3 .…”

“…Although it is difficult to detect an accurate sample current in this experiment to evaluate resistivity, usage of the measured κ' for the analysis according to Formula ( 6) is also available to determine Cp(V). Since the charge disproportionation and fluctuations affect the structure of low-energy phonons through the electron-lattice coupling, the low-temperature heat capacity changes drastically depending on the ground states of the charge degrees of freedom [20,28]. A peculiar feature was observed in the heat capacity of θ-(BEDT-TTF)2CsZn(SCN)4 by Yoshimoto et al in the normal condition [20].…”

“…Since the charge disproportionation and fluctuations affect the structure of low-energy phonons through the electron-lattice coupling, the low-temperature heat capacity changes drastically depending on the ground states of the charge degrees of freedom [20,28]. A peculiar feature was observed in the heat capacity of θ-(BEDT-TTF) 2 CsZn(SCN) 4 by Yoshimoto et al in the normal condition [20]. The temperature dependence of the lattice heat capacity divided by T 3 shows a large Boson peak structure around 2-3 K, which is a typical feature of molecular glasses and amorphous compounds [20,28,29].…”

“…Since the charge-lattice coupling is strong in the charge fluctuation compounds, the application of electronic currents that affects the short-range charge fluctuations may induce some changes in low-energy phonons in θ-(BEDT-TTF) 2 CsZn(SCN) 4 [20]. Heat capacity measurements with electric currents for conductive materials have never been performed, although those with the application of large electric fields for perfectly insulating samples have been performed by the adiabatic method [21][22][23] and the relaxation method by Lashly et al [24].…”