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 Chemistry Faculty. University of Valencia

 Mediterranean Sea.  Chemistry Faculty. University of Valencia. New molecular paramagnetic semiconductors, metals and superconductors Carlos J. Gómez-García Molecular Science Institute. Univ. of Valencia (Spain). Outline. Strategy towards multifunctional molecular materials

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 Chemistry Faculty. University of Valencia

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  1.  Mediterranean Sea  Chemistry Faculty. University of Valencia New molecular paramagnetic semiconductors, metals and superconductors Carlos J. Gómez-García Molecular Science Institute. Univ. of Valencia (Spain)

  2. Outline • Strategy towards multifunctional molecular materials • Hystorical background • ET salts with [M(ox)3]3- anions • BEST salts with [M(ox)3]3- anions • Conclusions

  3. Molecule A Molecule B Property A Property B Both properties Multifunctional Molecular materialsStrategy: hybrid approximation Sinergy Cancellation

  4. Multifunctional Materials Electrical Properties Donors + Magnetic anions Optical Properties Magnetic Properties

  5. Outline • Strategy towards multifunctional molecular materials • Hystorical background • ET salts with [M(ox)3]3- anions • BEST salts with [M(ox)3]3- anions • Conclusions

  6. 1954 per2Br 1st molecular metal [Fe(S2CNEt2)2Cl] 1972 1st molecular magnet 1973 (TTF)(TCNQ) 1st organic metal 1st organic SC 1981 (TM-TSF)(ClO4) HISTORY 1984 ET Salts Tc = 12 K multifunctionality 1991 A3C60 Tc = 45 K 1991 (ET)3[CuCl4].H2O 1st paramagnetic metal 1st paramagnetic SC 1995 (ET)4(H3O)[Fe(C2O4)3].PhCN l-(BETS)2[Fe0.5Ga0.5Cl4] 1996 2nd paramagnetic SC 1st metallic ferromagnet 2000 (ET)3[CrMn(C2O4)3]

  7. TM-TTF TTF BET-TTF O BEDO-TTF (BEDO) BEDT-TSF (BETS) Organic donors (cations) S Se BEDT-TTF (ET) BEDS-TTF (BEST)

  8. Molecular magnetic anions [MCl4]- [M(CN)6]3- [Fe(CN)5NO]2- [Fe2(C2O4)5]4- [M(C2O4)3]3-

  9. 7:2 3:1 11:3 7:2 14:4 5:1 1:1 4:1 5:1 4:1 1:1 2:1 3:1 3:1 4:1 4:1 4:1 3:2 4:1 4:1 9:2 2:1 4:1 2:1 2:1

  10. (TTF)4{MII(H2O)2[MIII(C2O4)3]2} [M’(H2O)6]2+ TTF [M(C2O4)3]3- Layered structure

  11. Only known k-type phase with TTF Discrete trinuclear anions [MII(H2O)2[MIII(ox)3]2]4- High Spin trinuclear complex S = 11/2 E. Coronado, C. J. Gómez-García et al. Adv. Mater.1996, 8, 737

  12. (ET)4[(H3O)M(C2O4)3].Solvent FirstParamagneticSuperconductor A. W. Graham, M. Kurmoo, P. Day Chem. Commun. 1995, 2061 BEDT-TTF (ET) [M(C2O4)3]3-

  13. ET4[AM(C2O4)3].D

  14. Ligand(dto,croc,...) Solvent (PhX, PhX2, PhOH,PhCOOH, PhCHO,PhCH3,...) Metal (Co, Mn,…) Cation (A+, Mn2+, Fe2+,... ) Donor(BEST, BEDO,…) Modifications superconductivity + ferromagnetism + optical activity (?)

  15. Outline • Strategy towards multifunctional molecular materials • Hystorical background • ET salts with [M(ox)3]3- anions • BEST salts with [M(ox)3]3- anions • Conclusions

  16. ET4[H3OM(ox)3].PhXMIII = Cr, X = Cl (6) and Br (7) MIII = Fe, X = Cl (8), Br (9) and F (10) BEDT-TTF (ET) [M(ox)3]3-M = Cr and Fe C6H5X (X = F, Cl and Br)

  17. ET4[H3OM(ox)3].PhXMIII = Cr, X = Cl (6) and Br (7) MIII = Fe, X = Cl (8), Br (9) and F (10) 1 mm

  18. 295 K ET4[H3OM(ox)3].PhXM = Cr, X = Cl (6), Br (7) M = Fe, X = Cl (8), Br (9), F (10) Layers parallel to the ab plane b” Phase Isostructural to Day’s salts although with a structural transition below  220 K

  19. 95 K ET4[H3OM(ox)3].PhXM = Cr, X = Cl (6), Br (7) M = Fe, X = Cl (8), Br (9), F(10) Also two different layers but now the layers are not equivalent B B A A B B A A D D C C D D C C

  20. 295 K ET4[H3OM(ox)3].PhXM = Cr, X = Cl (6), Br (7) M = Fe, X = Cl (8), Br (9), F(10) 6.30 Å 6.30 Å 6.39 Å 6.39 Å 6.30 Å 6.30 Å Distorted hexagonal cavity

  21. 95 K ET4[H3OM(ox)3].PhXM = Cr, X = Cl (6), Br (7) M = Fe, X = Cl (8), Br (9), F(10) contraction of four sides of the hexagon 6.30 Å 6.30 Å Distorted hexagonal cavity 6.30 Å 6.21 Å 6.39 Å 6.39 Å 6.33 Å 6.33 Å 6.30 Å 6.30 Å 6.21 Å 6.30 Å

  22. 295 K ET4[H3OM(ox)3].PhXM = Cr, X = Cl (6), Br (7) M = Fe, X = Cl (8), Br (9), F(10) 33.5º Tilted solvent molecule in-plane PhBr molecule 95 K 33.1º Tilted solvent molecule out-of-plane PhBr molecule

  23. Electrical Properties ET4[H3OCr(ox)3].PhCl (6)

  24. Electrical Properties ET4[H3OCr(ox)3].PhCl (6) s300K 10-2 S.cm-1 Metallic down to  120 K Charge localization

  25. Electrical Properties ET4[H3OCr(ox)3].PhCl (6) No SC transition above 0.4 K

  26. Electrical Properties ET4[H3OFe(ox)3].PhCl (8)

  27. Electrical Properties ET4[H3OFe(ox)3].PhCl (8) s300K 8.10-3 S.cm-1 Metallic down to  100 K Charge localization

  28. Electrical Properties ET4[H3OFe(ox)3].PhCl (8) No SC transition above 0.4 K

  29. Electrical Properties ET4[H3OCr(ox)3].PhBr (7)

  30. Electrical Properties ET4[H3OCr(ox)3].PhBr (7) Tc 1.9 K Metallic down to  50 K s300K 10-2 S.cm-1 Chargelocalization

  31. Electrical Properties ET4[H3OCr(ox)3].PhBr (7) onset at Tc 1.9 K zeroresistance at  0.4 K

  32. Electrical Properties ET4[H3OCr(ox)3].PhBr (7) H  layer(ab) T = 0.4 K Hc2||  50 mT Hint 4 mT

  33. Electrical Properties ET4[H3OCr(ox)3].PhBr (7) H  layer(ab) T = 0.4 K Hint 4 mT Hc2||  50 mT

  34. Electrical Properties ET4[H3OFe(ox)3].PhBr (9)

  35. Electrical Properties ET4[H3OFe(ox)3].PhBr (9) Tc 4.0 K Metallic down to  50 K s300K 5.10-3 S.cm-1 Chargelocalization

  36. Electrical Properties ET4[H3OFe(ox)3].PhBr (9) onset at Tc 4.0 K zeroresistance at  1.0 K

  37. Electrical Properties ET4[H3OFe(ox)3].PhBr (9) H  layer (ab)

  38. Electrical Properties ET4[H3OFe(ox)3].PhBr (9) H  layer (ab) Hc2 8 T

  39. Electrical Properties ET4[H3OFe(ox)3].PhBr (9) T = 0.4 K H layer(ab) Hc1 10 mT Hc2 8 T

  40. Electrical Properties ET4[H3OFe(ox)3].PhBr (9) Tc decreases with increasing currents

  41. Electrical Properties ET4[H3OFe(ox)3].PhF (10)

  42. Electrical Properties ET4[H3OFe(ox)3].PhF (10) Tc 1.2 K Chargelocalization s300K 102 S.cm-1 Metallic down to  250 K

  43. Electrical Properties ET4[H3OFe(ox)3].PhF (10) onset at Tc 1.2 K zeroresistance at T < 0.4 K

  44. Electrical Properties ET4[H3OFe(ox)3].PhF (10) H  layer (ab) Hc2> 2 T

  45. Electrical Properties ET4[H3OFe(ox)3].PhF (10) H  layer (ab) T = 0.4 K Hc2 4 T Hint 5.5 mT

  46. Electrical Properties ET4[H3OM(ox)3].PhX

  47. Magnetic Properties ET4[H3OM(ox)3].PhX Pauli Paramagnetism (TIP) + Paramagnetism (M)

  48. Magnetic Properties ET4[H3OFe(ox)3].PhBr (9) Hc1 10 mT Tc = 4.0 K Meissner Effect

  49. Magnetic Properties ET4[H3OFe(ox)3].PhBr (9) AC susceptibility (in-phase signal) Hc1 10 mT Meissner Effect

  50. Magnetic Properties ET4[H3OFe(ox)3].PhBr (9) Hc1 10 mT Tc = 4.0 K AC susceptibility (out-of-phase signal)

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