Theoretical investigations of oxygen vacancy effects in nickel-doped zirconia from ab initio XANES spectroscopy at the oxygen K-edge

• Dick Hartmann Douma,
• Lodvert Tchibota Poaty,
• Alessio Lamperti,
• Stéphane Kenmoe,
• Abdulrafiu Tunde Raji,
• Alberto Debernardi and
• Bernard M’Passi-Mabiala

Beilstein J. Nanotechnol. 2022, 13, 975–985, doi:10.3762/bjnano.13.85

• and magnetic order in a typical diluted magnetic oxide. Such a finding may be crucial for spintronics-related applications. Keywords: defect; ligand field; nickel; oxidation state; oxides; spectroscopy; spintronics; vacancy; X-ray absorption; X-ray absorption near-edge structure (XANES); zirconia

• with an electron configuration according to ligand field theory [46][47][48] (cf. Figure 2). This is because the two orbitals e and t2 participate together to the transitions occurring in the pre-edge region (Figure 4a). The atom Ni2 has similar site symmetry and electronic configurations with low

• and spin-down orbitals (Figure 4c). This orbital arrangement suggests that the nickel atom has an oxidation state of +3 and is in high spin-polarization with the valence electron configuration according to ligand field theory (cf. Figure 2). In the case of nickel atom Ni2, the contribution to the O

Low-energy electron interaction and focused electron beam-induced deposition of molybdenum hexacarbonyl (Mo(CO)₆)

• Po-Yuan Shih,
• Maicol Cipriani,
• Christian Felix Hermanns,
• Jens Oster,
• Klaus Edinger,
• Armin Gölzhäuser and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2022, 13, 182–191, doi:10.3762/bjnano.13.13

• elimination of d8 and d6 metal complexes is well-known [60][61][62] and the formation of multiple metal–metal bonds replacing the ligand field stabilization lost in this process has been shown for a number of dinuclear Mo and W coordination compounds [62]. In principle, electron attachment represents

Topographic signatures and manipulations of Fe atoms, CO molecules and NaCl islands on superconducting Pb(111)

• Carl Drechsel,
• Philipp D’Astolfo,
• Jung-Ching Liu,
• Thilo Glatzel,
• Rémy Pawlak and
• Ernst Meyer

Beilstein J. Nanotechnol. 2022, 13, 1–9, doi:10.3762/bjnano.13.1

• possibility to tune the magnetic anisotropy of a single porphyrin molecule by perturbing its ligand field with the STM probe [39][40]. These results not only suggest the importance of future manipulations experiments, but also shed new lights into the potential of decoupling atoms and molecules electronically

Adsorption of iron tetraphenylporphyrin on (111) surfaces of coinage metals: a density functional theory study

• Hao Tang,
• Nathalie Tarrat,
• Véronique Langlais and
• Yongfeng Wang

Beilstein J. Nanotechnol. 2017, 8, 2484–2491, doi:10.3762/bjnano.8.248

• between these two stable magnetic states is essentially associated to the strength of the ligand field. The modification of the coordination sphere of the metallic centre is thus necessary to manipulate its spin state. Most of such manipulations have been achieved by coordinating an additional small

• strong enough to modify the ligand-field environment of Fe. This result reveals that an external permanent element such as a STM tip or an additional molecule is needed to use FeTPP or similar molecules as model system for molecular spin switches. Method and Computational Details Spin-polarized DFT

Comprehensive investigation of the electronic excitation of W(CO)₆ by photoabsorption and theoretical analysis in the energy region from 3.9 to 10.8 eV

• Mónica Mendes,
• Khrystyna Regeta,
• Filipe Ferreira da Silva,
• Nykola C. Jones,
• Søren Vrønning Hoffmann,
• Gustavo García,
• Chantal Daniel and
• Paulo Limão-Vieira

Beilstein J. Nanotechnol. 2017, 8, 2208–2218, doi:10.3762/bjnano.8.220

• t2g(π)→t2g(π*) transitions, whereas Koerting et al. [6] at 6.24 and 6.54 eV report them as ligand-field (LF) 1A1g→1A1g symmetry forbidden transitions. It is interesting to note that in [9] an identical assignment was proposed for the feature at 6.51 eV while the calculation of Rosa et al. [15] only

Synthesis of [Fe(L_eq)(L_ax)]_n coordination polymer nanoparticles using blockcopolymer micelles

• Christoph Göbel,
• Ottokar Klimm,
• Florian Puchtler,
• Sabine Rosenfeldt,
• Stephan Förster and
• Birgit Weber

Beilstein J. Nanotechnol. 2017, 8, 1318–1327, doi:10.3762/bjnano.8.133

• axial ligands and/or solvent molecules. For octahedral complexes, a weak ligand field splitting leads to the occupation of antibonding orbitals (HS complexes) and by this supports ligand exchange. A fast ligand exchange will increase the probability of the formation of microcrystals outside the BCP

• micelle. In this case the templating effect of the BCP micelles does not work. In agreement with this consideration, the pure HS complex [FeLeq(bpee)]n with the weakest ligand field splitting is the first one where microcrystals are observed, while for the spin-crossover complexes [FeLeq(bpea)]n, [FeLeq

Phenalenyl-based mononuclear dysprosium complexes

• Yanhua Lan,
• Andrea Magri,
• Olaf Fuhr and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 995–1009, doi:10.3762/bjnano.7.92

• individual Ln sites along with the nature of the ligand field. Owing to a very strong Ising-type uniaxial anisotropy of the metal ion, dysprosium containing compounds are extensively studied and have been found to have the most promising slow-relaxation behavior. Typical examples are [Dy(acac)3(H2O)2] [8

• present in such a ligand field play an important role in facilitating tunneling or other magnetic relaxation processes [54]. This effect is consistent with the observation of true thermally activated relaxation resulting in a highly curved relaxation time down to the low temperature regime (Figure 5). The

Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

• Wen Yu,
• Frank Schramm,
• Eufemio Moreno Pineda,
• Yanhua Lan,
• Olaf Fuhr,
• Jinjie Chen,
• Hironari Isshiki,
• Wolfgang Wernsdorfer,
• Wulf Wulfhekel and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 126–137, doi:10.3762/bjnano.7.15

• ligand field of the metal complex, which is typically of a few nm in dimensions. It is proposed that the ultimate size limits of modern electronics and information processing can be tackled by such device geometry [1][2][3]. Research on compounds with single-molecule magnet (SMM) characteristics

Sub-monolayer film growth of a volatile lanthanide complex on metallic surfaces

• Hironari Isshiki,
• Jinjie Chen,
• Kevin Edelmann and
• Wulf Wulfhekel

Beilstein J. Nanotechnol. 2015, 6, 2412–2416, doi:10.3762/bjnano.6.248

• result of the quantum mechanical interaction of the local magnetic moment and the ligand field [1]. Lanthanide-based SMMs have attracted much interest due to the potentially huge energy barrier for the reversal of magnetization [2]. This is an advantage from an applications viewpoint for magnetic storage

A facile method for the preparation of bifunctional Mn:ZnS/ZnS/Fe₃O₄ magnetic and fluorescent nanocrystals

• Houcine Labiadh,
• Tahar Ben Chaabane,
• Romain Sibille,
• Lavinia Balan and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2015, 6, 1743–1751, doi:10.3762/bjnano.6.178

• dipole forbidden 4T1 → 6A1 ligand field transition [23][24][31]. Adding the magnetic Fe3O4 shell to the surface of Mn:ZnS/ZnS QDs progressively reduced the fluorescence intensity, which became very low especially for the Mn:ZnS/ZnS/Fe3O4 (3) material (Figure 5b,c). Note that the PL QY decreased from 10.8

The influence of molecular mobility on the properties of networks of gold nanoparticles and organic ligands

• Edwin J. Devid,
• Paulo N. Martinho,
• M. Venkata Kamalakar,
• Úna Prendergast,
• Christian Kübel,
• Tibebe Lemma,
• Jean-François Dayen,
• Tia. E. Keyes,
• Bernard Doudin,
• Mario Ruben and
• Sense Jan van der Molen

Beilstein J. Nanotechnol. 2014, 5, 1664–1674, doi:10.3762/bjnano.5.177

• σ-donor/π-acceptor ligands exhibiting an octahedral coordination environment with a coordination number of six for transition metals [14]. Moreover, in the case of iron(II) ions, the BPP-ligands adjust the ligand field strength to access the so-called ST or spin crossover (SCO) regime [15], in which

Quantum size effects in TiO₂ thin films grown by atomic layer deposition

• Massimo Tallarida,
• Chittaranjan Das and
• Dieter Schmeisser

Beilstein J. Nanotechnol. 2014, 5, 77–82, doi:10.3762/bjnano.5.7

• , the spectral features observed for very thin TiO2 films were addressed to a decreased ligand-field at TiO2/substrate interfaces, which was found to be increasingly important when moving from the MgO substrate to SiO2 [21]. Instead, Krüger used a first-principles multichannel multiple-scattering

• 1.5 nm to 2.25 nm. As mentioned above, the origin of this feature was attributed to hybridized Ti 3d/O 2p states, for which the two peaks appear because the Ti 3d orbital is split into t2g and eg bands by the ligand-field. The shape of 0.75 nm and 1.5 nm TiO2 films compares very well with that found

• different substrates. Kronawitter et al. addressed the changes at the O-K edge to a variation of the ligand-field at the interface, due to structural distortion and to a weaker Ti 3d/O 2p hybridization [11]. We further notice that the decrease of Ti 3d/O 2p hybridization in thinner films pairs up with the

Spin relaxation in antiferromagnetic Fe–Fe dimers slowed down by anisotropic Dy^III ions

• Valeriu Mereacre,
• Frederik Klöwer,
• Yanhua Lan,
• Rodolphe Clérac,
• Juliusz A. Wolny,
• Volker Schünemann,
• Christopher E. Anson and
• Annie K. Powell

Beilstein J. Nanotechnol. 2013, 4, 807–814, doi:10.3762/bjnano.4.92

• huge Ising-type magnetic anisotropy of many lanthanide ions, which can be controlled by designing the ligand field, can slow down the relaxation of magnetisation and can be an effective source for the modulation of properties of transition metal molecular magnets [1]. The anisotropy of the lanthanide

• is severely affected by the symmetry of the crystal field and it can be controlled by a suitable design of the ligand field environment [2][3]. Today, the orientation of the principal axes of the magnetization of the lanthanide ions in low-symmetry environments can be determined theoretically and

• anisotropy using simple ligand field considerations, but also because of its huge field dependence of the relaxation time [13]. Designing the ligand field environment can help to control the magnetic anisotropy of some of the later lanthanides [2][3], but this is less useful for the DyIII ion. The

Towards atomic resolution in sodium titanate nanotubes using near-edge X-ray-absorption fine-structure spectromicroscopy combined with multichannel multiple-scattering calculations

• Carla Bittencourt,
• Peter Krüger,
• Maureen J. Lagos,
• Xiaoxing Ke,
• Gustaaf Van Tendeloo,
• Chris Ewels,
• Polona Umek and
• Peter Guttmann

Beilstein J. Nanotechnol. 2012, 3, 789–797, doi:10.3762/bjnano.3.88

• structures and oxidation states. Here, the electronic structure of the nanotubes is discussed in terms of the ligand field splitting of the Ti ions and the connectivity of the TiO6 octahedral network. Among the different structures proposed for these nanotubes [13][14][15][16][17], it is currently accepted

• 2p1/2 (L2-edge) and 2p3/2 levels (L3-edge), corresponding to Ti(IV) in a tetragonal structure [36]. These levels are then further split by the strong ligand field arising from the surrounding oxygen atoms. For TiO6 octahedra, even if distorted, the cubic component dominates the ligand field [37]. The

• octahedral ligand field. The higher energy peaks (C, D and E) are due to more delocalized states that have been attributed to the hybridization of O p with Ti sp. In the (Na,H)TiNT spectrum, peaks A and B have nearly the same energy positions as in anatase, reflecting the octahedral coordination of Ti sites