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New materials for honeycomb-lattice and single-ion magnets

English title New materials for honeycomb-lattice and single-ion magnets
Applicant Krämer Karl
Number 172659
Funding scheme Project funding (Div. I-III)
Research institution Departement für Chemie und Biochemie Universität Bern
Institution of higher education University of Berne - BE
Main discipline Condensed Matter Physics
Start/End 01.08.2017 - 31.07.2021
Approved amount 528'066.00
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All Disciplines (2)

Discipline
Condensed Matter Physics
Inorganic Chemistry

Keywords (6)

magnetic excitations; material science; single ion magnets; quantum magnetism; AC magnetic susceptibility; neutron scattering

Lay Summary (German)

Lead
Das Ziel des Projekts sind die Entdeckung, Synthese, Kristallzüchtung und Charakterisierung neuer magnetischer Materialien, die als Modelsysteme für Kitaev Magnete und Einzel-Ionen Magnete dienen.
Lay summary

Neue Materialien für Kitaev Magnete.

Neue Materialen mit geometrisch frustrieten Strukturen auf zwei-dimensionalen (2-D) Hexagon-Gittern und analogen (10,3) 3-D Netzwerken werden synthetisiert und Kristalle gezüchtet. Metallionen mit kleinem Spin besetzen Gitterplätze mit C3 Symmetrie. Diese Materialien dienen als Modelsysteme für Kitaev Magnete. Das Kitaev Model besitzt einen spin liquid Quantengrundzustand und ist exakt lösbar. Die magnetischen Wechselwirkungen werden durch Neutronenstreuung an Kristallen untersucht. Kandidaten für diese Modelsysteme sind Seltenerdhalogenide MX3 und Ru3+ Oxalat Netzwerke.

 

Neue Seltenerdhalogenid Einzel-Ionen Magnete.

Einzel-Ionen Magnete tragen ihre Spin Information auf atomarem Niveau und sind daher von potentiellem Interesse für eine Datenspeicherung mit sehr hoher Dichte. Die neuen Materialien basieren auf Seltenerdhalogeniden mit dimeren Baugruppen und axialer Symmetrie. Das Kristallfeld erzeugt in diesen Verbindungen eine starke Ising Anisotropie, die z.B. Er3+ Spins parallel zur Dimerachse ausrichtet. Die Spin Ausrichtung und ihre Umkehr wird durch AC SQUID Messungen untersucht. Die Tunnelvorgänge zwischen den Spin Zuständen hängen von der Temperatur, dem Magnetfeld und der Überlappung der quantenmechanischen Wellenfunktionen ab. Durch chemische Variation der magnetischen Ionen und des Kristallgitters werden die Tunnelvorgänge verändert. Die relevanten Parameter werden untersucht, um die Tunnelvorgänge zu minimieren. Das Ziel sind die Erzeugung und Kontrolle langlebiger Spin Zustände.

Direct link to Lay Summary Last update: 25.07.2017

Responsible applicant and co-applicants

Employees

Publications

Publication
Field-induced anisotropy in the quasi-two-dimensional weakly anisotropic antiferromagnet [CuCl(pyz)2]BF4
Kwon Sungmin, Jeong M., Kubus M., Wehinger B., Krämer K. W., Rüegg Ch., Rønnow H. M., Lee Soonchil (2019), Field-induced anisotropy in the quasi-two-dimensional weakly anisotropic antiferromagnet [CuCl(pyz)2]BF4, in Physical Review B, 99(21), 214403-214403.
Quantum magnetism in molecular spin ladders probed with muon-spin spectroscopy
Lancaster T, Xiao F, Huddart B M, Williams R C, Pratt F L, Blundell S J, Clark S J, Scheuermann R, Goko T, Ward S, Manson J L, Rüegg Ch, Krämer K W (2018), Quantum magnetism in molecular spin ladders probed with muon-spin spectroscopy, in New Journal of Physics, 20(10), 103002-103002.
Giant Pressure Dependence and Dimensionality Switching in a Metal-Organic Quantum Antiferromagnet
Wehinger B., Fiolka C., Lanza A., Scatena R., Kubus M., Grockowiak A., Coniglio W. A., Graf D., Skoulatos M., Chen J.-H., Gukelberger J., Casati N., Zaharko O., Macchi P., Krämer K. W., Tozer S., Mudry C., Normand B., Rüegg Ch. (2018), Giant Pressure Dependence and Dimensionality Switching in a Metal-Organic Quantum Antiferromagnet, in Physical Review Letters, 121(11), 117201-117201.
Observation of two types of fractional excitation in the Kitaev honeycomb magnet
Janša Nejc, Zorko Andrej, Gomilšek Matjaž, Pregelj Matej, Krämer Karl W., Biner Daniel, Biffin Alun, Rüegg Christian, Klanjšek Martin (2018), Observation of two types of fractional excitation in the Kitaev honeycomb magnet, in Nature Physics, 14(8), 786-790.
Versatility of copper(II) coordination compounds with 2,3-bis(2-pyridyl)pyrazine mediated by temperature, solvents and anions choice
Melnic Elena, Kravtsov Victor Ch., Krämer Karl, van Leusen Jan, Decurtins Silvio, Liu Shi-Xia, Kögerler Paul, Baca Svetlana G. (2018), Versatility of copper(II) coordination compounds with 2,3-bis(2-pyridyl)pyrazine mediated by temperature, solvents and anions choice, in Solid State Sciences, 82, 1-12.
On the Border between Low-Nuclearity and One-Dimensional Solids: A Unique Interplay of 1,2,4-Triazolyl-Based {Cu II5 (OH) 2 } Clusters and Mo VI -Oxide Matrix
Lysenko Andrey B., Bondar Oksana A., Senchyk Ganna A., Rusanov Eduard B., Srebro-Hooper Monika, Hooper James, Prsa Krunoslav, Krämer Karl W., Decurtins Silvio, Waldmann Oliver, Liu Shi-Xia (2018), On the Border between Low-Nuclearity and One-Dimensional Solids: A Unique Interplay of 1,2,4-Triazolyl-Based {Cu II5 (OH) 2 } Clusters and Mo VI -Oxide Matrix, in Inorganic Chemistry, 57(10), 6076-6083.
Quasi-2D Heisenberg Antiferromagnets [CuX(pyz) 2 ](BF 4 ) with X = Cl and Br
Kubus Mariusz, Lanza Arianna, Scatena Rebecca, Dos Santos Leonardo H. R., Wehinger Björn, Casati Nicola, Fiolka Christoph, Keller Lukas, Macchi Piero, Rüegg Christian, Krämer Karl W. (2018), Quasi-2D Heisenberg Antiferromagnets [CuX(pyz) 2 ](BF 4 ) with X = Cl and Br, in Inorganic Chemistry, 57(9), 4934-4943.
Valence, exchange interaction, and location of Mn ions in polycrystalline MnxGa1−xN(x≤0.04)
Furrer A., Krämer K. W., Podlesnyak A., Pomjakushin V., Sheptyakov D., Safonova O. V. (2018), Valence, exchange interaction, and location of Mn ions in polycrystalline MnxGa1−xN(x≤0.04), in Physical Review B, 97(14), 140102-140102.
Hexanuclear Fe(III) wheels functionalized by amino-acetonitrile derivatives
Kravtsov Victor Ch., Malaestean Iurie, Stingach Eugenia P., Duca Gheorghe G., Macaev Fliur Z., van Leusen Jan, Kögerler Paul, Hauser Jürg, Krämer Karl, Decurtins Silvio, Liu Shi-Xia, Ghosh Ashta C., Garcia Yann, Baca Svetlana G. (2018), Hexanuclear Fe(III) wheels functionalized by amino-acetonitrile derivatives, in Solid State Sciences, 78, 156-162.
Low Temperature Phases of Na 2 Ti 3 Cl 8 Revisited
Hänni Nora, Frontzek Matthias, Hauser Jürg, Cheptiakov Denis, Krämer Karl (2017), Low Temperature Phases of Na 2 Ti 3 Cl 8 Revisited, in Zeitschrift für anorganische und allgemeine Chemie, 643(23), 2063-2069.
Exploration of a Variety of Copper Molybdate Coordination Hybrids Based on a Flexible Bis(1,2,4-triazole) Ligand: A Look through the Composition-Space Diagram
Senchyk Ganna A., Lysenko Andrey B., Domasevitch Konstantin V., Erhart Oliver, Henfling Stefan, Krautscheid Harald, Rusanov Eduard B., Krämer Karl W., Decurtins Silvio, Liu Shi-Xia (2017), Exploration of a Variety of Copper Molybdate Coordination Hybrids Based on a Flexible Bis(1,2,4-triazole) Ligand: A Look through the Composition-Space Diagram, in Inorganic Chemistry, 56(21), 12952-12966.
Dimensional reduction by pressure in the magnetic framework material CuF2(D2O)2 (pyz): From spin-wave to spinon excitations
Skoulatos M., Månsson M., Fiolka C., Krämer K. W., Schefer J., White J. S., Rüegg Ch. (2017), Dimensional reduction by pressure in the magnetic framework material CuF2(D2O)2 (pyz): From spin-wave to spinon excitations, in Physical Review B, 96(2), 020414-020414.
Coordination behavior of 1-(3,2′:6′,3″-terpyridin-4′-yl)ferrocene: Structure and magnetic and electrochemical properties of a tetracopper dimetallomacrocycle
Klein Y. Maximilian, Lanzilotto Angelo, Prescimone Alessandro, Krämer Karl W., Decurtins Silvio, Liu Shi-Xia, Constable Edwin C., Housecroft Catherine E. (2017), Coordination behavior of 1-(3,2′:6′,3″-terpyridin-4′-yl)ferrocene: Structure and magnetic and electrochemical properties of a tetracopper dimetallomacrocycle, in Polyhedron, 129, 71-76.
Dinuclear Complexes Formed by Hydrogen Bonds: Synthesis, Structure and Magnetic and Electrochemical Properties
Granelli Matteo, Downward Alan M., Huber Robin, Guénée Laure, Besnard Céline, Krämer Karl W., Decurtins Silvio, Liu Shi-Xia, Thompson Laurence K., Williams Alan F. (2017), Dinuclear Complexes Formed by Hydrogen Bonds: Synthesis, Structure and Magnetic and Electrochemical Properties, in Chemistry - A European Journal, 23(29), 7104-7112.
Tetranuclear {Co II2 Co III2 }, Octanuclear {Co II4 Co III4 }, and Hexanuclear {Co III3 Dy III3 } Pivalate Clusters: Synthesis, Magnetic Characterization, and Theoretical Modeling
Radu Ioana, Kravtsov Victor Ch., Ostrovsky Serghei M., Reu Oleg S., Krämer Karl, Decurtins Silvio, Liu Shi-Xia, Klokishner Sophia I., Baca Svetlana G. (2017), Tetranuclear {Co II2 Co III2 }, Octanuclear {Co II4 Co III4 }, and Hexanuclear {Co III3 Dy III3 } Pivalate Clusters: Synthesis, Magnetic Characterization, and Theoretical Modeling, in Inorganic Chemistry, 56(5), 2662-2676.

Associated projects

Number Title Start Funding scheme
105175 Magnetic excitations in low-dimensional compounds of transition metal ions 01.01.2005 Project funding (Div. I-III)
150257 Dimensional and Anisotropy Control of Model Quantum Magnets 01.01.2014 Project funding (Div. I-III)
132877 Magnetic Excitations in Low-Dimensional Arrays of Quantum Spins 01.01.2011 Project funding (Div. I-III)
121397 Sub-Kelvin high sensitivity magnetometer for magnetic materials exploration 01.07.2008 R'EQUIP
65120 Magnetic Neutron Scattering of Low Dimensional Transition Metal Ion Compounds 01.01.2002 Project funding (Div. I-III)
117817 Magnetic excitations in novel metal-organic quantum materials and molecular magnets 01.01.2008 Project funding (Div. I-III)
189644 Versatile high sensitivity and throughput magnetometer for quantum, functional and applied materials 01.03.2020 R'EQUIP

Abstract

We propose a major new initiative to discover and synthesize novel transition-metal and rare-earth-based materials. These compounds will serve as model systems in the search for Kitaev honeycomb lattices and new single-ion magnets. The fundamental phases and elementary excitations of honeycomb-lattice magnets will be studied by neutron spectroscopy and bulk experimental techniques. The single-ion magnets will be investigated by AC susceptibility SQUID measurements.Project A: New materials for honeycomb-lattice Kitaev-model magnets.The particular focus will be on materials with geometrically frustrated structure and a threefold symmetry at the metal ion site, such as the two-dimensional (2D) honeycomb lattice and the related (10,3) 3D network. Kitaev spin interactions may be realized on these lattices for magnetic ions with a small spin. The Kitaev model attracted significant interest because it has a quantum spin liquid ground state and is exactly solvable. Promising candidates for new model systems are YbBr3 and Ru3+ based oxalate networks. Also the crystal growth of alpha-RuCl3 will be investigated which is an established model material with a distorted 2D honeycomb lattice.Project B: Cs3Er2X9 (X = Cl - I) single-ion magnets.The new family of Cs3Er2X9 single-ion magnets was recently discovered by our group. These Er3+ halides show an extraordinary high out-of-phase chi’’ AC magnetic susceptibility. The crystal field creates a strong Ising anisotropy and aligns the J = 15/2 spins of Er3+ parallel to the dimer axis. Due to a detailed knowledge of the crystal structures and energies of the crystal field levels, these materials offer a plentitude of chemical variations for a deeper investigation of spin relaxation mechanisms. A full understanding of these mechanisms is required for a control of the spin states. Single-ion magnets carry their spin information on an atomic level which is of potential interest for high density data storage or related applications.
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