1
|
Rivic F, Schäfer R. Magnetism of single-doped paramagnetic tin clusters studied using temperature-dependent Stern-Gerlach experiments with enhanced sensitivity: impact of the diamagnetic ligand field and paramagnetic dopant. Phys Chem Chem Phys 2024; 26:12982-12992. [PMID: 38639064 DOI: 10.1039/d4cp00890a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
In this work, the magnetic properties of tetrel clusters SnNTM, which are singly doped with transition metals (TM), are investigated. On the one hand, the number of tetrel atoms (N = 11, 12, 14 and 17 with TM = Mn) is varied; on the other hand, different transition metals (N = 14, TM = Cr, Mn, Fe) are studied. Magnetic deflection experiments under cryogenic conditions show that the variation of the number of tetrel atoms strongly changes the magnetic properties of the Mn-doped clusters. It is observed that Sn12Mn, Sn11Mn and Sn14Mn partially show super-atomic behaviour, while spin relaxation occurs in Sn17Mn. Magnetic deflection experiments at higher nozzle temperatures were carried out for the first time enhanced by a second parallel-aligned Stern-Gerlach magnet to achieve larger deflections. The resulting temperature-dependent one-sided deflections are quantitatively analysed using Curie's law and show that Sn17Mn possesses the highest magnetic moment of these clusters, followed by Sn12Mn and Sn11Mn. Sn14Mn shows the lowest magnetic moment. The replacement of Mn by Cr in Sn14Mn leads to a diamagnetic singlet, i.e., the magnetic moment of Cr in Sn14Cr is completely quenched. The replacement of Mn by Fe in turn leads to a paramagnetic species, whereby Sn14Fe is most likely present as a triplet. On this basis, the geometrical and electronic structures are analysed using quantum chemical calculations, indicating an arachno-type structure for Sn14Cr, Sn14Mn and Sn14Fe, which has already been predicted in the literature for Si14Cr. This is experimentally confirmed by deflection of molecular beams with an electric field under cryogenic conditions, suggesting that the arachno-type geometry is crucial for the overall stability of the transition-metal-doped tetrel clusters Sn14TM with TM = Cr, Mn, Fe.
Collapse
Affiliation(s)
- Filip Rivic
- Technical University of Darmstadt, Eduard-Zintl-Institute, Peter-Grünberg-Straße 8, 64287 Darmstadt, Germany.
| | - Rolf Schäfer
- Technical University of Darmstadt, Eduard-Zintl-Institute, Peter-Grünberg-Straße 8, 64287 Darmstadt, Germany.
| |
Collapse
|
2
|
Rivic F, Lehr A, Fuchs TM, Schäfer R. Joint electric and magnetic beam deflection experiments and quantum chemical studies of MSn 12 clusters (M = Al, Ga, In): on the interplay of geometric structure and magnetic properties in nanoalloys. Faraday Discuss 2023; 242:231-251. [PMID: 36260024 DOI: 10.1039/d2fd00091a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
MSn12 clusters (M = Al, Ga, In) were studied in electric and magnetic beam deflection experiments at temperatures of 16 K and 30 K. For all three species, the results of the electric beam deflection experiments indicate the presence of two structural isomers of which one is considerably polar. The magnetic beam deflection experiments show atom-like beam splitting (superatomic behavior) with g-factors of 2.6-2.7 for a fraction of the clusters in the molecular beam, indicating significant spin-orbit coupling. On the one hand, we investigate by several experiments combining electric and magnetic deflectors how the superatomic and polar fractions are linked proving the correlation of the Stark and Zeeman effects. On the other hand, the magnetic deflection behavior is examined more thoroughly by performing quantum chemical calculations. By systematic distortion of an artificial icosahedral tin cage towards the global minimum structure, which has a pyritohedral geometry, the shifts in the magnitude of the g-factor are found to be mainly caused by a single dominant electronic excitation. This allows one to develop a semi-quantitative understanding of the magnetic behavior. On the basis of avoided crossings in the rotational Zeeman diagram, simulations of the magnetic beam deflection comprising computed rotational constants, vibrational modes, g-factors and spin-rotation coupling constants are performed which resemble our experimental findings in satisfactory agreement. With this, a better understanding of the magnetic properties of nanoalloy clusters can be achieved. However, the geometric structures of the polar isomers are still unknown.
Collapse
Affiliation(s)
- Filip Rivic
- Technical University of Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| | - Andreas Lehr
- Technical University of Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| | - Thomas M Fuchs
- Technical University of Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| | - Rolf Schäfer
- Technical University of Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| |
Collapse
|
3
|
Lehr A, Rivic F, Jäger M, Gleditzsch M, Schäfer R. Optical absorption and shape transition in neutral Sn N clusters with N ≤ 40: a photodissociation spectroscopy and electric beam deflection study. Phys Chem Chem Phys 2022; 24:11616-11635. [PMID: 35507965 DOI: 10.1039/d2cp01171a] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Neutral SnN clusters with N = 6-20, 25, 30, 40 are investigated in a joint experimental and quantum chemical study with the aim to reveal their optical absorption in conjunction with their structural evolution. Electric beam deflection and photodissociation spectroscopy are applied as molecular beam techniques at nozzle temperatures of 16 K, 32 K and 300 K. The dielectric response is probed following the approach in S. Schäfer et al., J. Phys. Chem A, 2008, 112, 12312-12319. It is improved on those findings and the cluster size range is extended in order to cover the prolate growth regime. The impact of the electric dipole moment, rotational temperature and vibrational excitation on the deflection profiles is discussed thoroughly. Photodissociation spectra of tin clusters are recorded for the first time, show similarities to spectra of silicon clusters and are demonstrated to be significantly complicated by the presence of multiphoton absorption in the low-energy region and large excess energies upon dissociation which is modelled by the RRKM theory. In both experiments two isomers for the clusters with N = 8, 11, 12, 19 need to be considered to explain the experimental results. Triple-capped trigonal prisms and double-capped square antiprisms are confirmed to be the driving building units for almost the entire size range. Three dominating fragmentation channels are observed, i.e. the loss of a tin atom for N < 12, a Sn7 fragment for N < 19 and a Sn10 fragment for N ≥ 19 with Sn15 subunits constituting recurring geometric motifs for N > 20. The prolate-to-quasispherical structural transition is found to occur at 30 < N ≤ 40 and is analyzed with respect to the observed optical behavior taking quantum chemical calculations and the Mie-Gans theory into account. Limitations of the experimental approach to study the geometric and electronic structure of the clusters at elevated temperatures due to vibrational excitation is also thoroughly discussed.
Collapse
Affiliation(s)
- Andreas Lehr
- Technical University of Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| | - Filip Rivic
- Technical University of Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| | - Marc Jäger
- Technical University of Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| | - Martin Gleditzsch
- Technical University of Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| | - Rolf Schäfer
- Technical University of Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| |
Collapse
|
4
|
Fuchs TM, Schäfer R. Influence of nuclear spins on electron spin coherence in isolated, p-doped tin clusters. Phys Chem Chem Phys 2021; 23:11334-11344. [PMID: 33959734 DOI: 10.1039/d1cp01227d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Magnetic double deflection experiments reveal that nuclear spins diminish electron spin coherence in isolated AlSn12 clusters. A temperature-dependent fraction of the endohedral cage clusters show superatomic response in Stern-Gerlach experiments which allows one to detect spin flips under controlled conditions in a double deflection arrangement. The concentration of nuclear spins in the tin cage is varied by using isotopically enriched tin samples. Hyperfine interaction, nuclear spin statistics and spin dynamics are discussed in detail. It is demonstrated that state-interference in the multistate Landau-Zener system AlSn12 explains why the spin decoherence is significantly increased when one or two nuclear spins are already present in the cluster, while the spin coherence no longer changes significantly with the addition of further nuclear spins.
Collapse
Affiliation(s)
- Thomas M Fuchs
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 8, Darmstadt, Germany.
| | - Rolf Schäfer
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 8, Darmstadt, Germany.
| |
Collapse
|
5
|
Rivic F, Fuchs TM, Schäfer R. Discriminating the influence of thermal excitation and the presence of structural isomers on the Stark and Zeeman effect of AlSn12 clusters by combined electric and magnetic beam deflection experiments. Phys Chem Chem Phys 2021; 23:9971-9979. [DOI: 10.1039/d1cp00351h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A combination of electric and magnetic beam deflection experiments shows a connection between non-polar and superatomic species for AlSn12 clusters.
Collapse
Affiliation(s)
- Filip Rivic
- Technische Universität Darmstadt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie
- 64287 Darmstadt
- Germany
| | - Thomas M. Fuchs
- Technische Universität Darmstadt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie
- 64287 Darmstadt
- Germany
| | - Rolf Schäfer
- Technische Universität Darmstadt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie
- 64287 Darmstadt
- Germany
| |
Collapse
|
6
|
Fuchs TM, Gleditzsch M, Schäfer R. Local coordination numbers of up to 19 in gadolinium–tin alloy nanoclusters. J Chem Phys 2020; 153:164308. [DOI: 10.1063/5.0027772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Thomas M. Fuchs
- Technische Universität Darmstadt, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
| | - Martin Gleditzsch
- Technische Universität Darmstadt, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
| | - Rolf Schäfer
- Technische Universität Darmstadt, Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
| |
Collapse
|
7
|
Affiliation(s)
- Jijun Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
| | - Qiuying Du
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
| | - Si Zhou
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
| | - Vijay Kumar
- Center for Informatics, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, Gautam Buddha Nagar 201314, U. P., India
- Dr. Vijay Kumar Foundation, 1969 Sector 4, Gurgaon 122001, Haryana, India
| |
Collapse
|
8
|
Gleditzsch M, Pašteka LF, Götz DA, Shayeghi A, Johnston RL, Schäfer R. Gold doping of tin clusters: exo- vs. endohedral complexes. NANOSCALE 2019; 11:12878-12888. [PMID: 31243419 DOI: 10.1039/c9nr03233a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present molecular beam electric deflection experiments on neutral gold-doped tin clusters. The experimental SnNAu (N = 6-16) cluster beam profiles are interpreted by means of classical trajectory simulations supplied, with cluster structures generated by a genetic algorithm based on density functional theory. The combined experimental and theoretical analysis confirms that at least nine tin atoms are necessary to form a cage that is capable of encapsulating a gold atom, with high symmetry only marginally distorted by the gold atom. Two-component DFT calculations reveal that for some clusters spin-orbit effects are necessary to properly describe these species. Partial charge analysis methods predict the presence of charge transfer effects from the tin host to the dopant, resulting in a negatively charged gold atom.
Collapse
Affiliation(s)
- Martin Gleditzsch
- Technische Universität Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| | - Lukáš F Pašteka
- Department of Physical and Theoretical Chemistry & Laboratory for Advanced Materials, Faculty of Natural Sciences, Comenius University, Mlynská dolina, Ilkovicova 6, 84215 Bratislava, Slovakia
| | - Daniel A Götz
- Technische Universität Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| | - Armin Shayeghi
- Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Roy L Johnston
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Rolf Schäfer
- Technische Universität Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany.
| |
Collapse
|
9
|
Gleditzsch M, Jäger M, Pašteka LF, Shayeghi A, Schäfer R. Doping effects on the geometric and electronic structure of tin clusters. Phys Chem Chem Phys 2019; 21:24478-24488. [DOI: 10.1039/c9cp05124d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In depth analysis of doping effects on the geometric and electronic structure of tin clusters via electric beam deflection, numerical trajectory simulations and density functional theory.
Collapse
Affiliation(s)
- Martin Gleditzsch
- Technische Universität Darmstadt
- Eduard-Zintl-Institut
- 64287 Darmstadt
- Germany
| | - Marc Jäger
- Technische Universität Darmstadt
- Eduard-Zintl-Institut
- 64287 Darmstadt
- Germany
| | - Lukáš F. Pašteka
- Department of Physical and Theoretical Chemistry & Laboratory for Advanced Materials
- Faculty of Natural Sciences
- Comenius University
- 84215 Bratislava
- Slovakia
| | - Armin Shayeghi
- Vienna Center for Quantum Science and Technology (VCQ)
- Faculty of Physics
- University of Vienna
- A-1090 Vienna
- Austria
| | - Rolf Schäfer
- Technische Universität Darmstadt
- Eduard-Zintl-Institut
- 64287 Darmstadt
- Germany
| |
Collapse
|