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Constant Resistivity State (CRS) below T c in l -(BETS) 2 Fe x Ga 1-x Cl 4. H. Kobayashi, H. Cui, K. Takahashi, A. Kobayashi. Development of Multi-functional Magnetic Molecular Conductors. Design and development of multi-functional conductors
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Constant Resistivity State (CRS) below Tc in l-(BETS)2FexGa1-xCl4 H. Kobayashi, H. Cui, K. Takahashi, A. Kobayashi Development of Multi-functional Magnetic Molecular Conductors Design and development of multi-functional conductors by assembling building blocks with different characters Synergy of building brocks with different functions s Magnetic superconductors exhibiting unprecedentedelectro-magnetic properties l-, k-(BETS)2FeX4 Photo-controllable magnetic conductor k-(BETS)2Fe(ox)Cl2 hn c [Fe(qsal)2][Ni(dmit)2]n Conductors based on p donors with stable org. radical parts (TTP-Proxyl)2FeCl4
New Molecular Conductor Exhibiting Photo-Controled Spin-Crossover Transition K. Takahashi [Fe(qsal)2] [Ni(dmit)2]3 n (n=1, 2, 3) n=3 [Fe(qsal)2] [Ni(dmit)2] Chem. Lett., 2005, 1240 ●cooling ●heating 830 nm LIESST (Light-induced excited spin state trapping) hn M s Photo-induced structural change Possibility of photo-controlable magnetic molecular conductors
C l C l C l C l S O O S S O M M ' M M ' O S O S O S C l C l C l C l M , M ' = F e , M n , C o . . . (p-Donor)/(Mag. Anion) *Tetrahalide anion ….l-. k-(BETS)2FeCl4 …. AFSC, FISC **Layered anion……(ET)4(H3O)Fe(C2O4)3(C6H5CN)…Paramag. SC [TTF][Fe(C2O4)Cl2] …Linear anion Bin Zhang Zhu Daoben M. Kurmoo 0.04 100 Oe Canted AF below 19.8 K FC 0.03 c/emu mol-1 0.02 ZFC 0.01 100 200 300 0 T/K k-(BETS)2Fe(ox)Cl2 k-type metalwithweakly ferromagneticanion chain r sRT= 85 S cm-1
a 4 b 10 H. Cui BETS FeCl4 x=1 r/ro 10 0 -1/4p 0 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● x=0 ● ● ● ● ● ● ● ● ● ● ● ● ● -10 GaCl4 ● ● ● ● ● c(emu/mol) ● -4 10 ● ● Hc Hdc= 0 Oe Amplitude=0.1Oe Frequency =0.5 Hz ● ● ● -20 ● ● ● ● ● 200 ● 100 300 0 ● ● ● -30 ● ● T/K ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● -40 2 4 3 T/K l-(BETS)2FexGa1-xCl4 conduction plane//ac 10 8 Metal 6 x0.45 T/K x0.45 4 SC Ins. 2 0 100 20 0 80 40 60 xcryst %
S. Uji ● a ● 30 b ● HJ /T 20 ● ★ ● ● ● ★ 10 ● ★ ● 0 0.2 0.4 0.6 0.8 1 0 x l-(BETS)2FeCl4 l-(BETS)2FexGa1-xCl4 S. Uji, L. Balicas, J. S. Brooks FISC H//c Brossard
8 x=0.45 H//c 6 ● ● ● ● ● ● ● ● PM ● T(K) ● S1 4 ● ● 0 ● ● ● ● ● ● ● ● ● ■ ■ ● ■ ● S2 ■ ● 2 S3 ● ■ ● ■ H//ac ■ AFI 0 10 20 0 30 ● ● ○ ○ x=0.45 H//b* 6 ● ● S. Uji S ● ● 4 T(K) ● ■ ● ■ ■ PM ■ ■ ● ■ ● AFI 2 ● ■ ■ ● 0 10 4 6 8 0 2 moH(T) 8 SC H//b* Ins.SCMetal switching l-BETS2FexGa1-xCl4(x0.45) B. Zhang, H. Tanaka
H. Cui l-(BETS)2FexGa1-xCl4 Hac H//ac (x0.42) H//ac Hac H//ac AFI
x 0.42 Hac H//ac 10 10 8 H//ac 8 Hac 6 T/K 6 T/K 4 4 2 2 0 0 0 15 10 0 5 15 10 5 H/T H/T l-(BETS)2FexGa1-xCl4 10 10 L. Brossard 8 8 Metal S. Uji, J. S. Brooks FeCl4 AFI 6 6 T/K T/K 4 4 SC Ins. Hc2// FISC (H//ac) 2 2 Hc2 l-(BETS)2GaCl4 at 2 K Hc2 12 T (H//a, c) 2.5 T (H//b*) (M. A. Tanatar et al.) 0 0 20 30 10 0 100 20 0 80 40 60 H/T (%) GaCl4 xcryst x 0.4
104 ● ● 102 r/W 100 M 10-2 100 SC 100 2 4 10 T/K 10-1 2.4 K 2.8 3.0 3.2 3.6 4.05 r/W 10-2 0 2 10 8 12 4 6 14 H/T H. Cui l-(BETS)2FexGa1-xCl4 (x0.37) r(H, T) Hac 104 1.0 K 1.4 2.0 103 102 101 r/W 100 10-1 10-2 10-3 0 2 10 12 4 6 8 14 H/T
104 ● ● 102 r/W 100 M 10-2 SC 2.5 K 2.8 3.2 3.5 3.7 4.1 4.5 100 2 4 10 T/K M CRS CRS 10 8 12 4 6 2 14 0 SC SC HengBo Cui r(H, T) of l-(BETS)2FexGa1-xCl4 (x0.37) H//ac 102 104 101 103 1.0 K 1.4 1.8 2.0 102 100 r/W 101 r/W 10-1 100 rm 10-1 10-2 rc 10-2 10-3 10-3 10 12 4 6 0 2 8 14 H/T rm/rc 6.4 H/T (CRS=Constant Resistivity State)
104 ● ● 102 r/W 100 M 10-2 SC 100 2 4 10 T/K Metal CRS r=const. Ins. HengBo Cui H-T Phase Diagram of l-(BETS)2FexGa1-xCl4 (x0.37) H//ac Hac Metal Ins.
10 8 Metal T/K 6 20 15 ● 4 SC Ins. x=0.37 rm/rc 6.4 rm / rc 10 ● ● 2 5 ● 0 0 0.3 0.4 0.2 1 x 0 0.8 0.4 0.6 xcryst l-(BETS)2FexGa1-xCl4 Constant Resistivity State (CRS) There exists the region of CRS in l-(BETS)2FexGa1-xCl4, where the resistivity is independent of T and H. CRS has been observed at least at 0.3<x<0.4 But CRS did not exist at x>0.42. The x-dependence of rc (resistivity of CRS): rm / rc (rm is the resistivity of metallic state just above Tc) increases with decreasing x: rm / rc 0.35 at x 0.4, 0. 7 at at x 0.37, 1.5 at x 0.3. Therefore, the critical conductivity (sc) seems to be linearly dependent on x. rm rc x=0.37 rm/rc 7.1 x=0.39 rm/rc 3.4 x0.3 rm/rc 16.1 rm rc 1 H/K
Development of Multi-functional Magnetic Molecular Conductors s New k-type BETS conductor with linear magnetic anions Photo-controllable magnetic conductor k-(BETS)2Fe(ox)Cl2 hn [Fe(qsal)2][Ni(dmit)2]n c B. Zhang, D. Zhu, M. Kurmoo K. Takahashi, O. Sato Possibility of Constant Resistivity State (CRS) below Tc in l-(BETS)2FexGa1-xCl4 H. Kobayashi, H. Cui, K. Takahashi, A. Kobayashi
Metal ● ● ● ● CLRS ● ● SC H. Cui x0.3 ● ● Hac H//ac rM/rc 15.6