Transport properties of organic conductor α-(BEDT-TTF)2I3 and θ-(BEDT-TTF)2I3 under hydrostatic pressure or uniaxial strain

被引:3
作者
Tajima, N [1 ]
Tajima, A
Tamura, M
Nishio, Y
Kajita, K
机构
[1] RIKEN, Condensed Mol Mat Lab, Wako, Saitama 3510198, Japan
[2] Toho Univ, Dept Phys, Funabashi, Chiba 2748510, Japan
关键词
narrow gap semiconductor; mobility; carrier density; pressure; uniaxial strain;
D O I
10.1016/S0379-6779(02)00339-9
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Pressure controlled switching between a metallic state and a semiconducting state was successfully realised on organic conductors alpha-(BEDT-TTF)(2)I-3 and theta-(BEDT-TTF)(2)I-3. Under high hydrostatic pressures, a-(BEDT-TTF)(2)I-3 behaves as an ultra-narrow gap (about 1 meV at p = 18 kbar) semiconductor. It is characterised by strongly temperature(T)-dependent carrier density. It decreases by about 106 times between 300 and I K. When strained in b-axis, on the other hand, this material was found to behave as a quasi-two-dimensional (Q2D) metal with a large Fermi surface. The carrier density is independent of T while conductivity increases by about 102 times between 300 and 4 K. theta-(BEDT-TTF)213 exhibits a similar change. Under the ambient pressure, it is a typical Q2D metal and changes to a narrow gap semiconductor under pressures above about 5 kbar. (C) 2002 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:147 / 149
页数:3
相关论文
共 5 条
[1]   SYNTHESIS, STRUCTURE AND PHYSICAL-PROPERTIES OF A TWO-DIMENSIONAL ORGANIC METAL, DI[BIS(ETHYLENE-DITHIOLO)TETRATHIOFULVALENE] TRIIODIDE, (BEDT-TTF)2+I3- [J].
BENDER, K ;
HENNIG, I ;
SCHWEITZER, D ;
DIETZ, K ;
ENDRES, H ;
KELLER, HJ .
MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 1984, 108 (3-4) :359-371
[2]   MAGNETOTRANSPORT PHENOMENA OF ALPHA-TYPE (BEDT-TTF)2I3 UNDER HIGH-PRESSURES [J].
KAJITA, K ;
OJIRO, T ;
FUJII, H ;
NISHIO, Y ;
KOBAYASHI, H ;
KOBAYASHI, A ;
KATO, R .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1992, 61 (01) :23-26
[3]   CRYSTAL AND ELECTRONIC-STRUCTURES OF LAYERED MOLECULAR SUPERCONDUCTOR, THETA-(BEDT-TTF)2(I3)1-X(AUI2)X [J].
KOBAYASHI, H ;
KATO, R ;
KOBAYASHI, A ;
NISHIO, Y ;
KAJITA, K ;
SASAKI, W .
CHEMISTRY LETTERS, 1986, (05) :833-836
[4]   Uniaxial strain method for soft crystals: Application to the control of the electronic properties of organic conductors [J].
Maesato, M ;
Kaga, Y ;
Kondo, R ;
Kagoshima, S .
REVIEW OF SCIENTIFIC INSTRUMENTS, 2000, 71 (01) :176-181
[5]   Transport property of an organic conductor α-(BEDT-TTF)2I3 under high pressure -: Discovery of a novel type of conductor [J].
Tajima, N ;
Tamura, M ;
Nishio, Y ;
Kajita, K ;
Iye, Y .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 2000, 69 (02) :543-551