Negative magnetoresistance and spin filtering of spin-coupled di-iron-oxo clusters

Wang, Ruining; Rodriguez, Jorge H.; Liu, Wu-Ming

doi:10.1103/physrevb.89.235414

Cited by 7 publications

(4 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Spin-polarized electronic structure (SPES) calculations have been used to accurately predict structuredependent 57 Fe Mössbauer parameters 4,5 while, at the same time, establishing correlations with other properties of iron ions such as their net charges, magnetic moments, and spin densities. 6 Thus, by means of spin-polarized calculations one can establish correlations between Mössbauer parameters and concomitant elec-tronic, magnetic and structural reorganizations of the host Bi 2 Se 3 material caused by iron substituents. Although some experimental techniques probe magnetic properties of a bulk sample, 57 Fe Mössbauer spectroscopy is a powerful technique to study local electronic, magnetic and structural properties of Fe substituents and their immediate structural environment.…”

Section: Introductionmentioning

confidence: 99%

Mössbauer parameters of Fe57 substituents in the topological insulator Bi2Se3

Rodriguez

2019

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

57 Fe Mössbauer spectroscopy can probe several local structural, electronic and magnetic properties of Fe-containing systems. However, to establish a direct relationship between these properties and a system's geometric structure, the experimental Mössbauer parameters need to be analyzed via electronic structure calculations. Herein, structural, electronic and magnetic effects of iron substituents in the topological insulator Bi2Se3, as uniquely probed by 57 Fe Mössbauer spectroscopy, have been determined via spin-polarized electronic structure calculations. The iron ion substituents, of nominal Fe 3+ (S = 5/2) oxidation and spin state, are unequivocally shown to substitute Bi 3+ sites in epitaxial Bi2Se3 thin-films used for Mössbauer measurements. Concomitant with iron substitution, localized structural rearrangements take place whereby the longer Bi-Se bonds of the native system are replaced by significantly shorter Fe-Se counterparts in the Fe-containing system. The resulting distorted-octahedral environment about substituent iron ions gives rise to characteristic Mössbauer parameters (δFe ≈ 0.51 mm/s, ∆EQ ≈ 0.20 mm/s) which have been calculated in excellent agreement with measured values for Fe-doped Bi2Se3 thin films. Consistent with a substituent Fe 3+ ion's nominal high-spin electronic configuration (t ↑↑↑ 2g e ↑↑ g ), an Fe-centered spin density has been established which, nevertheless, extends towards neighboring Se atoms via direct Fe-Se bonding and concomitant Fe(d)-Se(p) hybridization.

show abstract

Section: Introductionmentioning

confidence: 99%

Mössbauer parameters of Fe57 substituents in the topological insulator Bi2Se3

Rodriguez

2019

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…These incorporate openshell metal ions whose valence electrons are indirectly interacting via oxygen-mediated superexchange interactions. 1,2 Whereas some clusters are characterized by singlet (S = 0) spin ground states due to antiparallel ordering of their metalcentered magnetic moments, 1 others have appreciable ground state spin due to non-compensated antiparallel ordering leading to ferrimagnetic configurations. Examples of the latter class are the two thiophene-2-carboxylate functionalized Mn 12 single molecule magnets (SMMs) studied in this work whose manganese ions have ferrimagnetic configurations leading to net S = 19/2 or S = 20/2 spin ground states.…”

Section: Introductionmentioning

confidence: 99%

“…Of particular interest is the study of magneto-structural correlations in SMMs to explain the magnitudes of their technologically-relevant magnetic anisotropy barriers, U ≈ D[S 2 z ], to spin reversal (Fig. 1 and 2).…”

Section: Introductionmentioning

confidence: 99%

Geometric, electronic and magnetic structures of S = 19/2 and S = 20/2 thiophene-2-carboxylate functionalized Mn₁₂ single molecule magnets

Rodriguez

Ziegler

2015

Dalton Trans.

Self Cite

View full text Add to dashboard Cite

The geometric and magnetic structures of two structurally related, but magnetically inequivalent, single molecule magnets (SMMs) have been computationally characterized. The first SMM, with formula [Mn12O12(O2CC4H3S)16(H2O)2](-1) (I), has a half-integer spin (S(I) = 19/2) due to ferrimagnetic ordering. The second SMM, with formula Mn12O12(O2CC4H3S)16(H2O)4 (II), has an integer spin (S(II) = 20/2) and its geometric structure has been computationally predicted. Both SMMs include thiophene-2-carboxylate functional groups for potential use in molecular electronics. To determine structural and electronic differences between both SMMs, spin polarized density functional theory was applied to I and II. Hydrogen bonding of two and four Mn-bound water molecules in I and II, respectively, to thiophene-2-carboxylate oxygen atoms and inner cubane oxygen atoms is essential for structural stabilization of both complexes. The one-electron-reduction of I is concomitant with a structural asymmetry within its cubane whereby two ions, of nominal Mn(4+)(Si = 3/2) character, are inequivalent to the other two and acquire an incipient Mn(3+)(Si = 4/2) character. The geometric asymmetry in I provides an extra, albeit small, contribution to its zero field splitting and anisotropy barrier to spin reversal. Thus, despite its lower spin state, the anisotropy barrier of I is only slightly lower than that of II.

show abstract

“…Electronic transport through a single-molecule magnet (SMM) has been intensively studied both experimentally 1 2 3 4 5 6 7 8 9 10 11 and theoretically 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 due to its applications in molecular spintronics 27 , but these investigations were focused mainly on the differential conductance or average current. Although the shot noise of electron transport through a SMM has not yet been observed experimentally, new techniques based on carbon nanotubes have been proposed for its possible realization 28 .…”

mentioning

confidence: 99%

Negative differential conductance and super-Poissonian shot noise in single-molecule magnet junctions

Xue

Liang

Liu

2015

Sci Rep

Self Cite

View full text Add to dashboard Cite

Molecular spintroinic device based on a single-molecule magnet is one of the ultimate goals of semiconductor nanofabrication technologies. It is thus necessary to understand the electron transport properties of a single-molecule magnet junction. Here we study the negative differential conductance and super-Poissonian shot noise properties of electron transport through a single-molecule magnet weakly coupled to two electrodes with either one or both of them being ferromagnetic. We predict that the negative differential conductance and super-Poissonian shot noise, which can be tuned by a gate voltage, depend sensitively on the spin polarization of the source and drain electrodes. In particular, the shot noise in the negative differential conductance region can be enhanced or decreased originating from the different formation mechanisms of negative differential conductance. The effective competition between fast and slow transport channels is responsible for the observed negative differential conductance and super-Poissonian shot noise. In addition, we further discuss the skewness and kurtosis properties of transport current in the super-Poissonian shot noise regions. Our findings suggest a tunable negative differential conductance molecular device, and the predicted properties of high-order current cumulants are very interesting for a better understanding of electron transport through single-molecule magnet junctions.

show abstract

Negative magnetoresistance and spin filtering of spin-coupled di-iron-oxo clusters

Cited by 7 publications

References 66 publications

Mössbauer parameters of Fe57 substituents in the topological insulator Bi2Se3

Mössbauer parameters of Fe57 substituents in the topological insulator Bi2Se3

Geometric, electronic and magnetic structures of S = 19/2 and S = 20/2 thiophene-2-carboxylate functionalized Mn₁₂ single molecule magnets

Negative differential conductance and super-Poissonian shot noise in single-molecule magnet junctions

Contact Info

Product

Resources

About

Negative magnetoresistance and spin filtering of spin-coupled di-iron-oxo clusters

Cited by 7 publications

References 66 publications

Mössbauer parameters of Fe57 substituents in the topological insulator Bi2Se3

Mössbauer parameters of Fe57 substituents in the topological insulator Bi2Se3

Geometric, electronic and magnetic structures of S = 19/2 and S = 20/2 thiophene-2-carboxylate functionalized Mn12 single molecule magnets

Negative differential conductance and super-Poissonian shot noise in single-molecule magnet junctions

Contact Info

Product

Resources

About

Geometric, electronic and magnetic structures of S = 19/2 and S = 20/2 thiophene-2-carboxylate functionalized Mn₁₂ single molecule magnets