Crystal structures and physical properties of molecular metals and superconductors

1993年，我们获得了一种新的装置，用于冷却安装在四圆衍射仪（Oxford Cryostream Cooler）上的小晶体样品，并对新开发的金属C_<60>化合物的低温晶体结构进行了研究，温度降至90 K。研究结果已经发表[H。Kobayashi et al., j.a.m chem . soc。、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科学公司），配备了一个闭式循环氦制冷机[T-2000低温控制器（TRI研究公司）]。这种新x射线系统的最低温度极限约为9k。利用这一系统，我们已经检测了许多分子导电晶体。主要研究结果如下：(1)新型有机超导体（T_c=8K）晶体结构分析与紧束缚带计算；lambda-BETS_2GaCl_4和lambda-BETS_2GaBrCl_3 10 K, ... 更在美国(2)最近发现低温晶体的带隙结构和电子第k有机超导体kappa——1986年(BEDT-TTF) _2I_3发现我们周围的结构变化(3)检查金属绝缘体(MI)转换α- (BEDT-TTF) _2I_3 alpha-BETS_2I_3(4)检查可能的结构变化在lambda-MT_2Au MI过渡(CN) _2(5)低温（MeBr-DCNQI） _2Cu(6)晶体结构kappa-和lambda-BETS_2FeCl_4 MI跃迁可能波动效应的分析和检验(7)M (dmit) _2化合物α - [(CH_3) _2 (C_2H_5) _2 N] [Ni (dmit) _2] _2的低温结构测定和能带结构检验β -[(CH_3) _4N] [pd (dmit) _2] _2和α -[(CH_3) _2 (C_2H_5) _2N] [pd (dmit) _2] [pd (dmit) _2] _2 (8) α -[EDT-TTF] [Ni (dmit) _2]、γ -[EDT-TTF] [pd (dmit) _2]和[EDT-TTF] TaF_6的低温晶体结构和CDW跃迁可能性的研究(9)C_<60> x射线衍射图和晶格常数的温度依赖性。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