CALORIMETRIC OBSERVATION OF THE METAL-INSULATOR PHASE-TRANSITION IN ALPHA-(BEDT-TTF)2I3
CALORIMETRIC OBSERVATION OF THE METAL-INSULATOR PHASE-TRANSITION IN ALPHA-(BEDT-TTF)2I3
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DOI：
10.1016/0038-1098(91)90647-e
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发表时间：
1991-07-01
影响因子：
2.1
通讯作者：
ANZAI, H
中科院分区：
文献类型：
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作者：
FORTUNE, NA;MURATA, K;ANZAI, H
准二维“有机”导体 α-(BEDT-TTF)2I3 在接近 135 K 时经历金属到绝缘体的转变。我们首次在比热中观察到与这种金属-绝缘体转变相关的急剧、滞后的一级相变。我们发现熵变 DELTA-S 的下限为 94% (+/- 20%) Rln2 每摩尔 (2.4 mJ/g-K)，对应于潜热的下限 0.32 J/g。从转变下方和上方推断，我们估计转变时比热 DELTA-C 的变化几乎等于 1.4-mu-J/ 摩尔 K (3.2 mJ/g-K)。观察到的行为与准一维有机导体中的 Peierls 型和大库仑斥力 Mott-Hubbard 型金属-绝缘体转变显着不同。
The quasi-2D 'organic' conductor alpha-(BEDT-TTF)2I3 undergoes a metal to insulator transition near 135 K. We have observed for the first time in the specific heat a sharp, hysteretic, first order phase transition associated with this metal-insulator transition. We find a lower bound on the entropy change DELTA-S of 94% (+/- 20%) Rln2 per mole (2.4 mJ/g-K), corresponding to a lower bound for the latent heat of 0.32 J/g. Extrapolating from below and above the transition, we estimate the change in the specific heat DELTA-C at the transition to be almost-equal-to 1.4-mu-J/ mole K (3.2 mJ/g-K). The observed behavior differs significantly from both Peierls type and large Coulomb repulsion Mott-Hubbard type metal-insulator transitions in quasi-1D organic conductors.