Crystal structures and physical properties of molecular metals and superconductors

1993年，我们获得了一种用于冷却安装在四圆衍射仪（Oxford Cryostream Cooler）上的小晶体样品的新装置，并对新开发的金属C_3化合物进行了低至90 K的低温晶体结构研究。结果已经发表[H.小林等，<60>美国化学学会，116，3153 - 3154（1994）]。作为低温晶体结构研究的下一个重要步骤，我们最近开发了一种新的Weissenberg型低温成像板（IP）系统（MAC Science Co.，Inc.）配备有闭合循环氦制冷机[T-2000 Cryo Controller（TRI Research，Inc.）]。这个新的X射线系统的最低温度极限约为9K。利用这个系统，我们已经检验了许多分子导电晶体。主要结果如下：（1）在10 K温度下，对新的有机超导体Al_2O_3-BETS_2GaCl_4和Al_2O_3-BETS_2GaBrCl_3（T_c = 8K）进行了晶体结构分析和紧束缚能带计算 ...更多信息 我们最近发现的第一个K型有机超导体kappa-1的低温晶体和电子能带结构。（BEDT-TTF）_2I_3（1986年发现）（3）α-Al_2O_3的金属-绝缘体（MI）相变的结构变化（BEDT-TTF）_2I_3和α-BETS_2I_3（4）金属间化合物MT_2Au（CN）_2在MI转变时可能结构变化的研究（5）金属间化合物MT_2Au（CN）_2的低温结构（MeBr-DCNQI）_2Cu（6）kappa-和dibda-BETS_2FeCl_4的晶体结构分析和MI跃迁可能涨落效应的检验（7）M（dmit）_2化合物的低温结构测定和能带结构检验。α-[（CH_3）_2（C_2H_5）_2 N][Ni（dmit）_2]_2，beta-[（CH_3）_4N][pd（dmit）_2]_2和alpha-[（CH_3）_2（C_2H_5）_2N][pd（dmit）_2]_2（8）低-α-[EDT-TTF][Ni（dmit）_2]的温度晶体结构和CDW跃迁的可能性的检验，γ-[EDT-TTF][pd（dmit）_2]和[EDT-TTF] TaF_6的X射线衍射图和晶格常数随温度的变化。<60>少

In 1993, we obtained a new device used to cool small crystal specimens mounted on a fourcircle diffractometer (Oxford Cryostream Cooler) and made the low-temperature crystal structure investigation on the newly developed metallic C_<60> compounds down to 90 K.The results have been already published [H.Kobayashi et al., J.Am.Chem.Soc., 116,3153-3154(1994)]. As a next and important step of the low-temperature crystal structure studies we have recently developed a new Weissenberg-type low-temperature imaging plate (IP) system (MAC Science Co., Inc.) equipped with a closed-cycle helium refrigerator [T-2000 Cryo Controller (TRI Research, Inc.)]. The lowest temperature limit of this new X-ray system is about 9 K.By using this system, we have examined many molecular conducting crystals. The main results are as follows : (1) Crystal Structure analyzes and tight-binding band calculations on new organic superconductors (T_c=8K), lambda-BETS_2GaCl_4 and lambda-BETS_2GaBrCl_3 at 10 K,which have be … More en recently discovered by us (2) Low-temperature crystal and electronic band structures of the first K-type organic superconductor kappa- (BEDT-TTF) _2I_3 found by us in 1986 (3) Examination of the structure change around metal-insulator (MI) transitions of alpha- (BEDT-TTF) _2I_3 and alpha-BETS_2I_3 (4) Examination of possible structure change at MI transition of lambda-MT_2Au (CN) _2 (5) Low-temperature structure of (MeBr-DCNQI) _2Cu (6) Crystal structure analyzes and examination of the possible fluctuation effect of the MI transition of kappa- and lambda-BETS_2FeCl_4 (7) Determination of low-temperature structure and examination of band structure of M (dmit) _2 compounds, alpha- [(CH_3) _2 (C_2H_5) _2 N] [Ni (dmit) _2] _2, beta-[(CH_3) _4N] [pd (dmit) _2] _2 and alpha- [(CH_3) _2 (C_2H_5) _2N] [pd (dmit) _2] _2 (8) Low-temperature crystal structures and examination of the possibility of CDW transitions of alpha- [EDT-TTF] [Ni (dmit) _2], gamma- [EDT-TTF] [pd (dmit) _2] and [EDT-TTF] TaF_6 (9) Temperature dependences of X-Ray diffraction patterns and lattice constants of C_<60>. Less