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Professor Tom Lancaster's Outputs (121)

Extremely well isolated two-dimensional spin-1/2 antiferromagnetic Heisenberg layers with a small exchange coupling in the molecular-based magnet CuPOF (2020)
Journal Article
Opherden, D., Nizar, N., Richardson, K., Monroe, J., Turnbull, M., Polson, M., Vela, S., Blackmore, W., Goddard, P., Singleton, J., Choi, E., Xiao, F., Williams, R., Lancaster, T., Pratt, F., Blundell, S., Skourski, Y., Uhlarz, M., Ponomaryov, A., Zvyagin, S., …Landee, C. (2020). Extremely well isolated two-dimensional spin-1/2 antiferromagnetic Heisenberg layers with a small exchange coupling in the molecular-based magnet CuPOF. Physical Review B, 102(6), Article 064431. https://doi.org/10.1103/physrevb.102.064431

We report on a comprehensive characterization of the newly synthesized Cu2+-based molecular magnet [Cu(pz)2 (2-HOpy)2](PF6 )2 (CuPOF), where pz = C4H4N2 and 2-HOpy = C5H4NHO. From a comparison of theoretical modeling to results of bulk magnetometry,... Read More about Extremely well isolated two-dimensional spin-1/2 antiferromagnetic Heisenberg layers with a small exchange coupling in the molecular-based magnet CuPOF.

Origin of Magnetic Ordering in a Structurally Perfect Quantum Kagome Antiferromagnet (2020)
Journal Article
Arh, T., Gomilšek, M., Prelovšek, P., Pregelj, M., Klanjšek, M., Ozarowski, A., Clark, S., Lancaster, T., Sun, W., Mi, J.-X., & Zorko, A. (2020). Origin of Magnetic Ordering in a Structurally Perfect Quantum Kagome Antiferromagnet. Physical Review Letters, 125(2), Article 027203. https://doi.org/10.1103/physrevlett.125.027203

The ground state of the simple Heisenberg nearest-neighbor quantum kagome antiferromagnetic model is a magnetically disordered spin liquid, yet various perturbations may lead to fundamentally different states. Here we disclose the origin of magnetic... Read More about Origin of Magnetic Ordering in a Structurally Perfect Quantum Kagome Antiferromagnet.

Magnetism and Néel skyrmion dynamics in GaV4S8−ySey (2020)
Journal Article
Hicken, T., Holt, S., Franke, K., Hawkhead, Z., Štefančič, A., Wilson, M., Gomilšek, M., Huddart, B., Clark, S., Lees, M., Pratt, F., Blundell, S., Balakrishnan, G., & Lancaster, T. (2020). Magnetism and Néel skyrmion dynamics in GaV4S8−ySey. Physical Review Research, 2(3), Article 032001. https://doi.org/10.1103/physrevresearch.2.032001

We present an investigation of the influence of low levels of chemical substitution on the magnetic ground state and Néel skyrmion lattice (SkL) state in GaV4S8−ySey, where y=0,0.1,7.9, and 8. Muon-spin spectroscopy (μSR) measurements on y=0 and 0.1... Read More about Magnetism and Néel skyrmion dynamics in GaV4S8−ySey.

Establishing magneto-structural relationships in the solid solutions of the skyrmion hosting family of materials: GaV4S8−ySey (2020)
Journal Article
Štefančič, A., Holt, S. J., Lees, M. R., Ritter, C., Gutmann, M. J., Lancaster, T., & Balakrishnan, G. (2020). Establishing magneto-structural relationships in the solid solutions of the skyrmion hosting family of materials: GaV4S8−ySey. Scientific Reports, 10(1), Article 9813. https://doi.org/10.1038/s41598-020-65676-9

The GaV4S8−ySey (y = 0 to 8) family of materials have been synthesized in both polycrystalline and single crystal form, and their structural and magnetic properties thoroughly investigated. Each of these materials crystallizes in the Fˉ 43m space gro... Read More about Establishing magneto-structural relationships in the solid solutions of the skyrmion hosting family of materials: GaV4S8−ySey.

Near-ideal molecule-based Haldane spin chain (2020)
Journal Article
Williams, R. C., Blackmore, W. J., Curley, S. P., Lees, M. R., Birnbaum, S. M., Singleton, J., Huddart, B. M., Hicken, T. J., Lancaster, T., Blundell, S. J., Xiao, F., Ozarowski, A., Pratt, F. L., Voneshen, D. J., Guguchia, Z., Baines, C., Schlueter, J. A., Villa, D. Y., Manson, J. L., & Goddard, P. A. (2020). Near-ideal molecule-based Haldane spin chain. Physical Review Research, 2(1), Article 013082. https://doi.org/10.1103/physrevresearch.2.013082

The molecular coordination complex NiI2 (3, 5-lut)4 [where (3,5-lut) = (3,5-lutidine) = (C7H9N)] has been synthesized and characterized by several techniques including synchrotron x-ray diffraction, electron-spin resonance, superconducting quantum in... Read More about Near-ideal molecule-based Haldane spin chain.

Enhancing easy-plane anisotropy in bespoke Ni(II) quantum magnets (2020)
Journal Article
Manson, J. L., Manson, Z. E., Sargent, A., Villa, D. Y., Etten, N. L., Blackmore, W. J., Curley, S. P., Williams, R. C., Brambleby, J., Goddard, P. A., Ozarowski, A., Wilson, M. N., Huddart, B. M., Lancaster, T., Johnson, R. D., Blundell, S. J., Bendix, J., Wheeler, K. A., Lapidus, S. H., Xiao, F., …Singleton, J. (2020). Enhancing easy-plane anisotropy in bespoke Ni(II) quantum magnets. Polyhedron, 180, Article 114379. https://doi.org/10.1016/j.poly.2020.114379

We examine the crystal structures and magnetic properties of several S = 1 Ni(II) coordination compounds, molecules and polymers, that include the bridging ligands HF2-, AF62- (A = Ti, Zr) and pyrazine or non-bridging ligands F-, SiF62-, glycine, H2O... Read More about Enhancing easy-plane anisotropy in bespoke Ni(II) quantum magnets.

Investigating the magnetic ground state of the skyrmion host material Cu2OSeO3 using long-wavelength neutron diffraction (2019)
Journal Article
Franke, K., Dean, P., Hatnean, M. C., Birch, M., Khalyavin, D., Manuel, P., Lancaster, T., Balakrishnan, G., & Hatton, P. (2019). Investigating the magnetic ground state of the skyrmion host material Cu2OSeO3 using long-wavelength neutron diffraction. AIP Advances, 9(12), Article 125228. https://doi.org/10.1063/1.5129400

We present long-wavelength neutron diffraction data measured on both single crystal and polycrystalline samples of the skyrmion host material Cu2OSeO3. We observe magnetic satellites around the (01⎯⎯1) diffraction peak not accessible to other techniq... Read More about Investigating the magnetic ground state of the skyrmion host material Cu2OSeO3 using long-wavelength neutron diffraction.

Determining the anisotropy and exchange parameters of polycrystalline spin-1 magnets (2019)
Journal Article
Blackmore, W., Brambleby, J., Lancaster, T., Clark, S., Johnson, R., Singleton, J., Ozarowski, A., Schlueter, J., Chen, Y.-S., Arif, A., Lapidus, S., Xiao, F., Williams, R., Blundell, S., Pearce, M., Lees, M., Manuel, P., Villa, D., Villa, J., Manson, J., & Goddard, P. (2019). Determining the anisotropy and exchange parameters of polycrystalline spin-1 magnets. New Journal of Physics, 21(9), https://doi.org/10.1088/1367-2630/ab3dba

Although low-dimensional S = 1 antiferromagnets remain of great interest, difficulty in obtaining highquality single crystals of the newest materials hinders experimental research in this area. Polycrystalline samples are more readily produced, but t... Read More about Determining the anisotropy and exchange parameters of polycrystalline spin-1 magnets.

Increased lifetime of metastable skyrmions by controlled doping (2019)
Journal Article
Birch, M., Takagi, R., Seki, S., Wilson, M., Kagawa, F., Štefančič, A., Balakrishnan, G., Fan, R., Steadman, P., Ottley, C., Crisanti, M., Cubitt, R., Lancaster, T., Tokura, Y., & Hatton, P. (2019). Increased lifetime of metastable skyrmions by controlled doping. Physical review B - Condensed Matter and Materials Physics, 100(1), Article 014425. https://doi.org/10.1103/physrevb.100.014425

Previous observations of metastable magnetic skyrmions have shown that close to the equilibrium pocket the metastable state has a short lifetime, and therefore, rapid cooling is required to generate a significant skyrmion population at low temperatur... Read More about Increased lifetime of metastable skyrmions by controlled doping.

Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF2(pyz) and [Ln(hfac)3(boaDTDA)] n (Ln  =  Sm, La) using implanted muons (2019)
Journal Article
Lancaster, T., Huddart, B., Williams, R., Xiao, F., Franke, K., Baker, P., Pratt, F., Blundell, S., Schlueter, J., Mills, M., Maahs, A., & Preuss, K. (2019). Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF2(pyz) and [Ln(hfac)3(boaDTDA)] n (Ln  =  Sm, La) using implanted muons. Journal of Physics: Condensed Matter, 31(39), Article 394002. https://doi.org/10.1088/1361-648x/ab2cb6

We present the results of muon-spin relaxation (SR) measurements on antiferromagnetic and ferromagnetic spin chains. In antiferromagnetic CuF2(pyz) we identify a transition to long range magnetic order taking place at K, allowing us to estimate a rat... Read More about Probing magnetic order and disorder in the one-dimensional molecular spin chains CuF2(pyz) and [Ln(hfac)3(boaDTDA)] n (Ln  =  Sm, La) using implanted muons.

Local magnetism, magnetic order and spin freezing in the "nonmetallic metal" FeCrAs (2019)
Journal Article
Huddart, B., Birch, M. T., Pratt, F., Blundell, S., Porter, D. G., Clark, S. J., …Lancaster, T. (2019). Local magnetism, magnetic order and spin freezing in the "nonmetallic metal" FeCrAs. Journal of Physics: Condensed Matter, 31(28), Article 285803. https://doi.org/10.1088/1361-648x/ab151f

We present the results of x-ray scattering and muon-spin relaxation (SR) measurements on the iron-pnictide compound FeCrAs. Polarized non-resonant magnetic x-ray scattering results reveal the 120° periodicity expected from the suggested three-fold sy... Read More about Local magnetism, magnetic order and spin freezing in the "nonmetallic metal" FeCrAs.

Emergence and topological order in classical and quantum systems (2019)
Journal Article
McLeish, T., Pexton, M., & Lancaster, T. (2019). Emergence and topological order in classical and quantum systems. Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics, 66, 155-169. https://doi.org/10.1016/j.shpsb.2019.02.006

There has been growing interest in systems in condensed matter physics as a potential source of examples of both epistemic and ontological emergence. One of these case studies is the fractional quantum Hall state (FQHS). In the FQHS a system of elect... Read More about Emergence and topological order in classical and quantum systems.

Unconventional Field-Induced Spin Gap in an S=1/2 Chiral Staggered Chain (2019)
Journal Article
Liu, J., Kittaka, S., Johnson, R., Lancaster, T., Singleton, J., Sakakibara, T., Kohama, Y., van Tol, J., Ardavan, A., Williams, B., Blundell, S., Manson, Z., Manson, J., & Goddard, P. (2019). Unconventional Field-Induced Spin Gap in an S=1/2 Chiral Staggered Chain. Physical Review Letters, 122(5), Article 057207. https://doi.org/10.1103/physrevlett.122.057207

We investigate the low-temperature magnetic properties of the molecule-based chiral spin chain ½CuðpymÞðH2OÞ4SiF6 · H2O (pym ¼ pyrimidine). Electron-spin resonance, magnetometry and heat capacity measurements reveal the presence of staggered g tensor... Read More about Unconventional Field-Induced Spin Gap in an S=1/2 Chiral Staggered Chain.

Spin Jahn-Teller antiferromagnetism in CoTi2O5 (2019)
Journal Article
Kirschner, F. K., Johnson, R. D., Lang, F., Khalyavin, D. D., Manuel, P., Lancaster, T., Prabhakaran, D., & Blundell, S. J. (2019). Spin Jahn-Teller antiferromagnetism in CoTi2O5. Physical Review B, 99(6), Article 064403. https://doi.org/10.1103/physrevb.99.064403

We have used neutron powder diffraction to solve the magnetic structure of orthorhombic CoTi2O5, showing that the long-range ordered state below 26 K identified in our muon-spin rotation experiments is antiferromagnetic with propagation vector k = (±... Read More about Spin Jahn-Teller antiferromagnetism in CoTi2O5.

Spin dynamics and field-induced magnetic phase transition in the honeycomb Kitaev magnet α−Li2IrO3 (2019)
Journal Article
Choi, S., Manni, S., Singleton, J., Topping, C., Lancaster, T., Blundell, S., …Coldea, R. (2019). Spin dynamics and field-induced magnetic phase transition in the honeycomb Kitaev magnet α−Li2IrO3. Physical Review B, 99(5), Article 054426. https://doi.org/10.1103/physrevb.99.054426

The layered honeycomb iridate α-Li2IrO3 displays an incommensurate magnetic structure with counterrotating moments on nearest-neighbor sites, proposed to be stabilized by strongly frustrated anisotropic Kitaev interactions between spin-orbit entangle... Read More about Spin dynamics and field-induced magnetic phase transition in the honeycomb Kitaev magnet α−Li2IrO3.

Magnetic order and enhanced exchange in the quasi-one-dimensional molecule-based antiferromagnet Cu(NO3)2(pyz)3 (2018)
Journal Article
Huddart, B., Brambleby, J., Lancaster, T., Goddard, P., Xiao, F., Blundell, S. J., Pratt, F. L., Singleton, J., Macchi, P., Scatena, R., Barton, A., & Manson, J. L. (2019). Magnetic order and enhanced exchange in the quasi-one-dimensional molecule-based antiferromagnet Cu(NO3)2(pyz)3. Physical Chemistry Chemical Physics, 21(3), 1014-1018. https://doi.org/10.1039/c8cp07160h

The quasi-one-dimensional molecule-based Heisenberg antiferromagnet Cu(NO3)2(pyz)3 has an intrachain coupling J = 13.7(1) K (Image ID:c8cp07160h-t1.gif) and exhibits a state of long-range magnetic order below TN = 0.105(1) K. The ratio of interchain... Read More about Magnetic order and enhanced exchange in the quasi-one-dimensional molecule-based antiferromagnet Cu(NO3)2(pyz)3.

Proposal for a micromagnetic standard problem for materials with Dzyaloshinskii–Moriya interaction (2018)
Journal Article
Cortés-Ortuño, D., Beg, M., Nehruji, V., Breth, L., Pepper, R., Kluyver, T., Downing, G., Hesjedal, T., Hatton, P., Lancaster, T., Hertel, R., Hovorka, O., & Fangohr, H. (2018). Proposal for a micromagnetic standard problem for materials with Dzyaloshinskii–Moriya interaction. New Journal of Physics, 20(11), Article 113015. https://doi.org/10.1088/1367-2630/aaea1c

Understanding the role of the Dzyaloshinskii–Moriya interaction (DMI) for the formation of helimagnetic order, as well as the emergence of skyrmions in magnetic systems that lack inversion symmetry, has found increasing interest due to the significan... Read More about Proposal for a micromagnetic standard problem for materials with Dzyaloshinskii–Moriya interaction.

Origin of skyrmion lattice phase splitting in Zn-substituted Cu2OSeO3 (2018)
Journal Article
Štefančič, A., Moody, S., Hicken, T., Birch, M., Balakrishnan, G., Barnett, S., Crisanti, M., Evans, J., Holt, S., Franke, K., Hatton, P., Huddart, B., Lees, M., Pratt, F., Tang, C., Wilson, M., Xiao, F., & Lancaster, T. (2018). Origin of skyrmion lattice phase splitting in Zn-substituted Cu2OSeO3. Physical Review Materials, 2(11), Article 111402(R). https://doi.org/10.1103/physrevmaterials.2.111402

We present an investigation into the structural and magnetic properties of Zn-substituted Cu2OSeO3, a system in which the skyrmion lattice (SkL) phase in the magnetic field–temperature phase diagram was previously seen to split as a function of incre... Read More about Origin of skyrmion lattice phase splitting in Zn-substituted Cu2OSeO3.