Hyperfine structure and exchange coupling with conduction electrons in the quasi-one-dimensional organic metal<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Co</mml:mi></mml:mrow><mml:mrow><mml:mn>0.01</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Ni</mml:mi></mml:mrow><mml:mrow><mml:mn>0.99</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi

Simonyan, Mkhital; Yonehara, Y.; Ding, Yuqin; Yakushi, Kyuya

doi:10.1103/physrevb.63.113103

Cited by 5 publications

(4 citation statements)

References 21 publications

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“…The Lorentzian shape of the single EPR absorption line, which suggests the strong magnetic exchange interaction between the verdazyl cation and [Ni(dmit) 2 ] - anion spins, was observed for the Ni salt ( 1 ). In such a case, the temperature dependence of the g -value of the Ni salt ( 1 ) is given by eq 2 , where the g V + and g Ni − are the g -values of the verdazyl cation and [Ni(dmit) 2 ] - anion, respectively. χ V + ( T ) and χ Ni − ( T ) will correspond to χ Curie - Weiss ( T ) and χ 1D - Alt ( T ) in eq 1, respectively.…”

Section: Discussionmentioning

confidence: 99%

Magnetic Semiconductor: Structural, Magnetic, and Conducting Properties of the Salts of the 6-Oxoverdazyl Radical Cation with M(dmit)₂ Anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

Mukai

Hatanaka

et al. 2002

Inorg. Chem.

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Five kinds of (1:1), (1:3), and (2:1) salts of 3-[4-(diethylmethylammonio)phenyl]-1,5-diphenyl-6-oxoverdazyl radical cation [V](+) with M(dmit)(2) anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate) ([V](+)[Ni(dmit)(2)](-) (1), [V](+)[Ni(dmit)(2)](3)(-) (2), [V](+)(2)[Zn(dmit)(2)](2-) (3), [V](+)(2)[Pd(dmit)(2)](2-) (4), and [V](+)(2)[Pt(dmit)(2)](2-) (5)) and an iodide salt of [V](+) ([V](+)[I](-) (6)) have been prepared, and the magnetic susceptibilities (chi(M) values) have been measured between 1.8 and 300 K. The chi(M) of the (1:1) Ni salt (1) can be well reproduced by the sum of the contributions from (i) a Curie-Weiss system with a Curie constant (C) of 0.376 K emu/mol and a negative Weiss constant (theta) of -1.5 K and (ii) the one-dimensional Heisenberg antiferromagnetic alternating chain system with 2J(A-B)/k(B) = -274 K (alternation parameter alpha = J(A-C)/J(A-B) = 0.2). The chi(M) of the (1:3) Ni salt (2) can be well explained by the two-term contributions from (i) the Curie-Weiss system with C = 0.376 K emu/mol and theta = -5.0 K and (ii) the dimer system with 2J/k(B) = -258 K. The magnetic properties of 1 and 2 were discussed based on the results obtained by crystal structure analysis and ESR measurements of 1 and 2. The chi(M) values of the (2:1) Zn, Pd, Pt salts 3, 4, and 5 and [V](+)[I](-) salt 6 follow the Curie-Weiss law with C = 0.723, 0.713, 0.712, and 0.342 K emu/mol and theta = -2.8, -3.1, -2.6, and +0.02 K, respectively, indicating that only the spins of the verdazyl radical cation contribute to the magnetic property of these salts. The salts 1, 3, and 5 are insulators. On the other hand, the conductivity (sigma) of the Ni salt 2 and Pd salt 4 at 20 degrees C was sigma = 8.9 x 10(-2) and 1.3 x 10(-4) S cm(-)(1) with an activation energy E(A) = 0.11 and 0.40 eV, respectively. The salts 2 and 4 are new molecular magnetic semiconductors.

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Section: Discussionmentioning

confidence: 99%

Magnetic Semiconductor: Structural, Magnetic, and Conducting Properties of the Salts of the 6-Oxoverdazyl Radical Cation with M(dmit)₂ Anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

Mukai

Hatanaka

et al. 2002

Inorg. Chem.

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“…Recent emerging research on Pcs involves their magnetic properties in a one-dimensional array or in a thin-film form. − Although the research on the magnetism of organic materials in bulk form has a long history, recent investigations of such a low-dimensional system have been motivated by the expectation that the magnetism of those systems may be remarkably different from that in bulk. One of the objectives in the research field called molecular magnetism is to control the magnetic properties at the scale of an individual molecule or single molecule layer.…”

Section: Introductionmentioning

confidence: 99%

Spin Polarization of Metal (Mn, Fe, Cu, and Mg) and Metal-Free Phthalocyanines on an Fe(100) Substrate

Suzuki

Kurahashi

et al. 2002

J. Phys. Chem. B

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The electronic structure and spin asymmetry of metal phthalocyanines (Pcs) (metal = Mn, Fe, Cu, and Mg) and metal-free Pc thin films of 1-monolayer (ML) thickness on an Fe(100) substrate were investigated using spin-polarized metastable deexcitation spectroscopy (SPMDS). The surface density-of-states (SDOS) of these Pcs observed in MDS was almost identical, and thus, insensitivity of the Pc electronic structure to the variation of the central metal atoms is indicated. On the other hand, the spin asymmetry in the SPMDS measurements exhibited noticeable differences among Pcs. These results are discussed from the viewpoint of the Pcs electronic structure calculated by a discrete variational X α method. The fact that differences are found in the spin asymmetry but not in SDOS among Pcs indicates an important role of the central metal atoms for spin polarization.

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“…The metal-phthalocyanine molecule is advantageous, since it provides the -d interaction between the electron conduction of the phthalocyanine molecular orbitals and the local moment of the central transition metal. [5][6][7][8] Figure 1(a) shows the dicyano(phthalocyaninato)iron [Fe(Pc)(CN) 2 ] molecule. 9) In this letter, we report the magnetoresistance and its dependence on the magnetic field angle in the Fe(Pc)(CN) 2 molecular complexes.…”

mentioning

confidence: 99%

Giant Negative Magnetoresistance Reflecting Molecular Symmetry in Dicyano(phthalocyaninato)iron Compounds

et al. 2006

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Materials containing Fe(Pc)(CN) 2 dicyano(phthalocyaninato)iron molecules show a giant negative magnetoresistance from the interaction between the conduction and the local moment. Under a magnetic field, the resistance becomes two orders of magnitude smaller than the zero-field resistance. The magnetic-field-angle dependence of the magnetoresistance reflects the symmetry of the Fe(Pc)(CN) 2 molecule. We discuss, according to the scaling relation, the correlation between the magnetoresistance and the molecular spin fluctuation. The giant response of spin-dependent transport has made many important contributions to physics and has been applied to magnetic storage and sensors, such as gigantic magnetoresistance.1) For molecular application, giant magnetoresistance in molecular materials is a key phenomenon. The intermolecular or intramolecular interaction between the conduction and the local moments is indispensable. Several studies have focused on molecular conductors having an interaction (-d interaction) between the molecules contributing to the conduction of the electron and the other molecules contributing to the magnetism of the d electron.2,3) In these conductors, it is important to control the molecular arrangement in the crystal. 4) If a single molecule contributes to both the electron conduction and the local moments, one can expect the possibility of an intramolecular -d interaction independent of the molecular arrangement. The physical properties resulting from the intramoleculard interaction can be realized not only in the crystal but in other various forms, such as film. The metal-phthalocyanine molecule is advantageous, since it provides the -d interaction between the electron conduction of the phthalocyanine molecular orbitals and the local moment of the central transition metal. 9) In this letter, we report the magnetoresistance and its dependence on the magnetic field angle in the Fe(Pc)(CN) 2 molecular complexes. The various Fe(Pc)(CN) 2 complexes show a giant negative magnetoresistance reflecting the molecular symmetry. The -d interaction causes a giant negative magnetoresistance in various compounds, in spite of the different molecular arrangements. Because the CN ligands of the Fe(Pc)(CN) 2 molecule markedly improve its solubility, the CN-ligands enable not only the growth of the molecular crystal but also the fabrication of a molecular thin film by a wet process. The needlelike single crystal is synthesized by the electrochemical method.9,11) The proportions of iron and cobalt atoms in the alloy TPP[Fe x Co 1Àx (Pc)(CN) 2 ] 2 are investigated by electron probe micro analysis (EPMA). Gold wires were glued with gold paint to the sample surface, and dc resistance was measured. A constant current (or voltage) was applied along the c axis, and sample voltage (or current) was measured. The experiments were performed with an 18 T superconducting magnet and a pulse magnet.

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Hyperfine structure and exchange coupling with conduction electrons in the quasi-one-dimensional organic metalCo0.01Ni0.99

Cited by 5 publications

References 21 publications

Magnetic Semiconductor: Structural, Magnetic, and Conducting Properties of the Salts of the 6-Oxoverdazyl Radical Cation with M(dmit)₂ Anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

Magnetic Semiconductor: Structural, Magnetic, and Conducting Properties of the Salts of the 6-Oxoverdazyl Radical Cation with M(dmit)₂ Anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

Spin Polarization of Metal (Mn, Fe, Cu, and Mg) and Metal-Free Phthalocyanines on an Fe(100) Substrate

Giant Negative Magnetoresistance Reflecting Molecular Symmetry in Dicyano(phthalocyaninato)iron Compounds

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Hyperfine structure and exchange coupling with conduction electrons in the quasi-one-dimensional organic metalCo0.01Ni0.99

Cited by 5 publications

References 21 publications

Magnetic Semiconductor: Structural, Magnetic, and Conducting Properties of the Salts of the 6-Oxoverdazyl Radical Cation with M(dmit)2 Anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

Magnetic Semiconductor: Structural, Magnetic, and Conducting Properties of the Salts of the 6-Oxoverdazyl Radical Cation with M(dmit)2 Anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

Spin Polarization of Metal (Mn, Fe, Cu, and Mg) and Metal-Free Phthalocyanines on an Fe(100) Substrate

Giant Negative Magnetoresistance Reflecting Molecular Symmetry in Dicyano(phthalocyaninato)iron Compounds

Contact Info

Product

Resources

About

Magnetic Semiconductor: Structural, Magnetic, and Conducting Properties of the Salts of the 6-Oxoverdazyl Radical Cation with M(dmit)₂ Anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

Magnetic Semiconductor: Structural, Magnetic, and Conducting Properties of the Salts of the 6-Oxoverdazyl Radical Cation with M(dmit)₂ Anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate)