Kim Lefmann

Search results

• 2011

  McStas-model of the Delft SESANS

  Knudsen, E., Udby, L., Willendrup, P. K., Lefmann, K. & Bouwman, W. G., 1 Jun 2011, In: Physica B: Condensed Matter. 406, 12, p. 2361-2364

  Research output: Contribution to journal › Journal article › Research › peer-review
  12 Citations (Scopus)

• McXtrace: a modern ray-tracing package for x-ray instrumentation

  Knudsen, E. B., Prodi, A., Willendrup, P. K., Lefmann, K., Baltser, J., Gundlach, C., Sanchez del Rio, M., Ferrero, C. & Feidenhans'l, R. K., 23 Sep 2011, In: Proceedings of SPIE. 8141, p. 81410G-81410G-7

  Research output: Contribution to journal › Conference article › Research › peer-review
  9 Citations (Scopus)

• Optimal shape of a cold-neutron triple-axis spectrometer

  Lefmann, K., Filges, U., Treue, F., Kirkensgaard, J. J. K., Plesner, B., Hansen, K. S. & Klenø, K. H., 1 Apr 2011, In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 634, 1 (Suppl. 1), p. S1-S6 6 p.

  Research output: Contribution to journal › Conference article › Research › peer-review
  7 Citations (Scopus)

• Powder diffractometers at long-pulsed sources: Proceedings of the International Workshop on Neutron Applications on Strongly Correlated Electron Systems 2011 (NASCES11)

  Sales, M., Holm, S. L., Lieutenant, K. & Lefmann, K., 20 Dec 2011, In: Journal of the Physical Society of Japan. 80, Suppl.B, p. SB018 4 p.

  Research output: Contribution to journal › Conference article › Research › peer-review
  4 Citations (Scopus)

• Spin reorientation in a-Fe₂O₃ nanoparticles induced by interparticle exchange interactions in a-Fe₂O₃/NiO nanocomposites

  Frandsen..[et al.], C., Lefmann, K., Lebech, B., Bahi, C. R. H., Brok, E., Ancona, S. N. & Theil Kuhn, L., 22 Dec 2011, In: Physical Review B Condensed Matter. 84, 21, p. 214435 10 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
  13 Citations (Scopus)

• Status of the danish Neutron Scattering Society

  Lefmann, K., 1 Mar 2011

  Research output: Other contribution › Communication

• Thermal chopper spectrometer for the European spallation source: Proceedings of the International Workshop on Neutron Applications on Strongly Correlated Electron Systems 2011 (NASCES11)

  Klenø, K. H. & Lefmann, K., 20 Dec 2011, In: Journal of the Physical Society of Japan. 80, Sppl.B, p. SB004

  Research output: Contribution to journal › Conference article › Research › peer-review
  4 Citations (Scopus)

• Using McStas for modelling complex optics, using simple building bricks

  Willendrup, P. K., Udby, L., Knudsen, E., Farhi, E. & Lefmann, K., 1 Apr 2011, In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 634, Sp.1, p. S150-S155

  Research output: Contribution to journal › Conference article › Research › peer-review
  7 Citations (Scopus)
• 2010

  Field-induced tomonaga-luttinger liquid phase two-leg spin 1/2 ladder with strong leg interactions

  Hong...[et al.], T., Kim, Y. H., Hotta, C. & Lefmann, K., 23 Sep 2010, In: Physical Review Letters. 105, 13, p. 137207 4 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
  95 Citations (Scopus)

• Simulation of a suite of generic long-pulse neutron instruments to optimize the time structure of the European Spallation Source accelerator: Report to ESS-SAC

  Lefmann, K., Filges, U., Holm, S. L., Klenø, K. H., Lieutenant, K., Knudsen, E., von Moos, L., Sales, M. & Willendrup, P. K., 1 Oct 2010

  Research output: Other contribution › Research
• 2009

  Anomalous spin waves in the commensurate-incommensurate magnetic phase transition in  LiNiPO₄

  Jensen, T. B. S., Christensen, N. B. & Lefmann, K., 2009, In: Physical Review B Condensed Matter. 79, 9, p. 092413

  Research output: Contribution to journal › Journal article › Research › peer-review
  35 Citations (Scopus)

• Design and simulation of instruments for a long-pulsed spallation source - ESS

  Lefmann, K., Willendrup, P. K., Knudsen, E., Larsen, F. K., Lieutenant, K., Habitch, K., Strobl, M., Kleno, K. H., Voigt, J., Frielinghaus, H., Manoshin, S., Stahn, J., Kohlbrecher, J., Filges, U., Farhi, E., Bentley, P., Cubitt, B., Wiedenmann, A., Regnault, L-P., Menelle, A. & 12 others, Goukassov, A., Rodriguez-Carvajal, J., Cuello, G., Tucker, M. G., Webster, J. R. P., Percival, A., Granroth, G., Robertson, L., Nylander, T., Mortensen, K., Vettier, C. & Mezei, F., 2009. 1 p.

  Research output: Contribution to conference › Conference abstract for conference › Research

  Open Access

  File
  24 Downloads (Pure)

• Field-induced competing interactions for ferroelectric polarization in  LiNiPO₄

  Jensen, T. B. S., Christensen, N. B., Kenzelmnn, M., Rønnow, H. M., Niedermayer, C., Andersen, N. H., Lefmann, K., Schefer, J., Zimmermann, M. V., Li, J., Zarestsky, J. L. & Vaknin, D., 2009, In: Physical Review B Condensed Matter. 79, 9, p. 092412

  Research output: Contribution to journal › Journal article › Research › peer-review
  58 Citations (Scopus)

• Long-Pulse Neutron Instrumentation Workshop, August 26-28, 2009

  Crawford, R. K., Arai, M., Carlile, C., Chapon, L., Granroth, G., Langridge, S., Lefmann, K., Mezei, F., Monkenbusch, M., Muhrer, G. & Wiedenmann, A., 26 Aug 2009, Oak Ridge, USA

  Research output: Other contribution › Research

  File
  903 Downloads (Pure)

• Magnetic-field-induced soft-mode quantum phase transition in the high-temperature superconductor La_1.855 Sr_0.145 CuO₄: An inelastic neutron-scattering study

  Chang, J., Christensen, N. B. & Lefmann, K., 2009, In: Physical Review Letters. 102, 17, p. 177006

  Research output: Contribution to journal › Journal article › Research › peer-review
  48 Citations (Scopus)

• Magnetic ordering in electronically phase-separated La(2-x)Sr(x)CuO(4+y): Neutron diffraction experiments

  Udby, L., Andersen, N. H., Chou, F. C., Christensen, N. B., Emery, S. B., Lefmann, K., Lynn, J. W., Mohottala, H. E., Niedermayer, C. & Wells, B. O., 2009, In: Physical Review B Condensed Matter. 80, p. 014505 5 p.

  Research output: Contribution to journal › Journal article › Research › peer-review

• Magnetic ordering in electronically phase-separated La_2-x Sr_x CuO_4+y: Neutron diffraction experiments

  Udby, L., Chou, F. C., Christensen, N. B., Emery, S. B., Lefmann, K., Lynn, J. W., Mohottala, H. E., Niedermayer, C. & Wells, B. O., 6 Aug 2009, In: Physical Review B - Condensed Matter and Materials Physics. 80, 1, 014505.

  Research output: Contribution to journal › Journal article › Research › peer-review
  9 Citations (Scopus)

• Neutron optics and Monte Carlo simulations in NMI3

  Böni, P. & Lefmann, K., 2009, In: Neutron News. 20, 1, p. 26-29 3 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
• 2008

  Avoided crossing of rattler modes in thermoelectric materials

  Christensen, M., Abrahamsen, A. B., Christensen, N. B., Juranyi, F., Andersen, N. H., Lefmann, K., Andreasson, J., Bahl, CRH. & Iversen, B. B., 2008, In: Nature Materials. 7, 10, p. 811-815

  Research output: Contribution to journal › Journal article › Research › peer-review
  583 Citations (Scopus)

• Reduction of data from inverted-geometry time-of-flight instruments

  Tregenna-Piggott, P. L. W., Juryani, F., Christiansen, P., Willendrup, P. & Lefmann, K., 2008, In: Journal of Neutron Research. 16, 1&2, p. 13-22 9 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
  4 Citations (Scopus)

• Simulation of a multiple-wavelength time-of-fligt neutron spectrometer for a long-pulsed spallation source

  Lefmann, K., Schober, H. & Mezei, F., 2008, In: Measurement Science and Technology. 19, 3, p. 034025 12 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
  7 Citations (Scopus)

• Tailored instrumentation for long-pulse neutron spallation sources

  Schober, H., Farhi, E., Mezei, F., Andersen, K., Bentley, P. M., Christiansen, P. & Lefmann, K., 2008, In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 589, 1, p. 34-46 12 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
  31 Citations (Scopus)

• Uniform spin wave modes in antiferromagnetic nanoparticles with uncompensated moments

  Bahl, C. R. H., Garde, J., Lefmann, K., Jensen, T. B. S., Lindegård, P-A., Madsen, D. E. & Mørup, S., 2008, In: European Physical Journal B. Condensed Matter and Complex Systems. 62, 1, p. 53-57 22 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
  12 Citations (Scopus)

• Virtual experiments: the ultimate aim of neutron ray-tracing simulations

  Lefmann, K., Willendrup, P. K., Udby, L., Lebech, B., Mortensen, K., Birk, J. O., Klenø, K. H., Knudsen, E., Christiansen, P., Saroun, J., Kulda, J., Filges, U., Konnecke, M., Tregenna-Piggott, P., Peters, J., Lieutenant, K., Zsigmond, G., Bentley, P. & Fahri, E., 2008, In: Journal of Neutron Research. 16, 3-4, p. 97-111 15 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
  31 Citations (Scopus)
• 2006

  Inelastic neutron scattering experiments with the monochromatic imaging mode of the RITA-II spectrometer

  Bahl, C. R. H., Lefmann, K., Abrahamsen, A. B., Rønnow, H. M., Saxild, F., Jensen, T. B. S., Udby, L. & Andersen, N. H., 1 May 2006, In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 246, 2, p. 452-462

  Research output: Contribution to journal › Journal article › Research › peer-review

  22 Citations (Scopus)

• Neutron study of magnetic excitations in 8-nm α-Fe₂O₃ nanoparticles

  Kuhn, L. T., Lefmann, K., Bahl, C. R. H., Nyborg Ancona, S., Lindgård, P-A., Frandsen, C., Madsen, D. E. & Steen, M., 3 Nov 2006, In: Physical Review B. 74, 184406.

  Research output: Contribution to journal › Journal article › Research › peer-review

• Realizing the full potential of a RITA spectrometer

  Lefmann, K., Abrahamsen, A. B., Bahl, C. R. H., Christensen, N. B., Jacobsen, H. S., Larsen, T. L., Häflinger, P., Filges, U. & Rønnow, H. M., 27 Nov 2006, In: Physica B: Condensed Matter. 385-386, 2, p. 1083-1085

  Research output: Contribution to journal › Conference article › Research › peer-review

  25 Citations (Scopus)
• 2005

  Oriented attachment and exchange coupling of α-Fe₂O₃ nanoparticles

  Frandsen, C., Bahl, C. R. H., Lebech, B., Lefmann, K., Theil Kuhn, L., Keller, L., Andersen, N. H., v.Zimmermann, M., Johnson, E., Klausen, S. N. & Mørup, S., 6 Dec 2005, In: Physical Review B. 72, 214406.

  Research output: Contribution to journal › Journal article › Research › peer-review
• 2004

  Dynamics in γ-Fe₂O₃ nanoparticles studied by time-of-flight polarized neutron scattering

  Theil Kuhn, L., Lefmann, K., Klausen, S. N., Rønnow, H. M., Murani, A. & Srewart, R., 3 Sep 2004, In: Physica B: Condensed Matter. 350, p. e217-e219

  Research output: Contribution to journal › Conference article › Research › peer-review

  5 Citations (Scopus)

• Magnetic anisotropy and quantized spin waves in hematite nanoparticles

  Klausen, S. N., Lefmann, K., Lindgård, P-A., Kuhn, L. T., Bahl, C. R. H., Frandsen, C., Mørup, S., Roessli, B., Cavadini, N. & Niedermayer, C., 9 Dec 2004, In: Physical Review B. 70, 214411.

  Research output: Contribution to journal › Journal article › Research › peer-review
  32 Citations (Scopus)

• Monte Carlo simulations as a part of the configuration for neutron instruments

  Andersen, P., Lefmann, K., Kuhn, L. T., Willendrup, P. K. & Farhi, E., 3 Sep 2004, In: Physica B: Condensed Matter. 350, p. e721-e724

  Research output: Contribution to journal › Conference article › Research › peer-review

  5 Citations (Scopus)

• Neutron diffraction study of anomalous high-field magnetic phases in TmNi₂B₂C

  Toft, K. N., Abrahamsen, A. B., Eskildsen, M. R., Lefmann, K., Andersen, N. H., Vorderwisch, P., Smeibidl, P., Meissner, M. & Canfield, P. C., 15 Jun 2004, In: Physical Review B. 69, 214507.

  Research output: Contribution to journal › Journal article › Research › peer-review

• The monochromatic imaging mode of a RITA-type neutron spectrometer

  Bahl, C. R. H., Andersen, P., Klausen, S. N. & Lefmann, K., 1 Dec 2004, In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 228, 4, p. 667-681

  Research output: Contribution to journal › Journal article › Research › peer-review
  16 Citations (Scopus)
• 2003

  An inelastic neutron scattering study of hematite nanoparticles

  Klausen, S. N., Lefmann, K., Lindgård, P-A., Klausen, N. K., Hansen, M. F., Bødker, F., Mørup, S. & Telling, M., 1 Oct 2003, In: Journal of Magnetism and Magnetic Materials. 266, 1-2, p. 68-78

  Research output: Contribution to journal › Conference article › Research › peer-review
  22 Citations (Scopus)
• 2002

  Comment on "Spin Dynamics of the 2D Spin Quantum Antiferromagnet Copper Deuteroformate Tetradeuterate (CFTD)"

  Rønnow, H. M., McMorrow, D. F., Coldea, R., Harrison, A., Youngson, I. D., Perring, T. G., Aeppli, G., Syljuåsen, O. F., Lefmann, K. & Rischel, C., 30 Jun 2002, In: Physical Review Letters. 89, 079702.

  Research output: Contribution to journal › Journal article › Research › peer-review

• Magnetic propertie of nanoparticales of antiferromagnetic materials

  Mørup, S., Frandsen, C., Bødker, F., Klausen, S. N., Lefmann, K., Lindgård, P-A. & Hansen, M. F., 12 Jan 2002, In: Hyperfine Interactions. 144-145, 1-4, p. 347-357

  Research output: Contribution to journal › Journal article › Research › peer-review
  47 Citations (Scopus)
• 2001

  Spin Dynamics of the 2D Spin ½ Quantum Antiferromagnet Copper Deuteroformate Tetradeuterate (CFTD)

  Rønnow, H. M., McMorrow, D. F., Goldea, R., Harrison, A., Youngson, I. D., Perring, T. G., Aeppli, G., Syljuåsen, O. F., Lefmann, K. & Rischel, C., 28 Jun 2001, In: Physical Review Letters. 87, 037202.

  Research output: Contribution to journal › Journal article › Research › peer-review
  102 Citations (Scopus)
• 2000

  Double-Spin-Flip Resonance of Rhodium Nuclei at Positive and Negative Spin Temperatures

  Tuoriniemi, J. T., Nummila, K. K., Lefmann, K., Knuuttila, T. A., Yao, W. & Rasmussen, F. B., 10 Jan 2000, In: Physical Review Letters. 84, p. 370-373

  Research output: Contribution to journal › Journal article › Research › peer-review
  9 Citations (Scopus)

• Thermodynamics of Rh nuclear spins calculated by exact diagonalization

  Lefmann, K., Ipsen, J., Rasmussen, F. B. & Rasmussen, F. B., 1 Jan 2000, In: Physica B: Condensed Matter. 284-288, PART II, p. 1702-1703 2 p.

  Research output: Contribution to journal › Journal article › Research

  1 Citation (Scopus)
• 1997

  Nuclear order in silver at pico-Kelvin temperature

  Siemensmeyer, K., Clausen, K. N., Lefmann, K., Lounasmaa, O. V., Metz, A., Nummila, K. K., Steiner, M., Tuoriniemi, J. T., Vuorinen, R. T. & Rasmussen, F. B., 2 Jun 1997, In: Physica B: Condensed Matter. 234-236, p. 768-769 2 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
• 1996

  Dynamical correlation functions of the S=½ nearest-neighbor and Haldane-Shastry Heisenberg antiferromagnetic chains in zero and applied fields

  Lefmann, K. & Rischel, C., 1 Sep 1996, In: Physical Review B. 54, p. 6340-6350

  Research output: Contribution to journal › Journal article › Research › peer-review

• kernemagnetisk orden i sølv, verden 3. koldeste forsøg ( Nuclear magnetic order in silver the 3^rd coldest experiment ever)

  Lefmann, K. & Rasmussen, F. B., 1 Mar 1996, In: Kvant. 8

  Research output: Contribution to journal › Journal article › Communication

• Neutron diffraction determination of the nuclear spin ordering in Cu and Ag at nano- and subnano-K temperatures

  Steiner, M., Metz, A., Siemensmeyer, K., Lounasmaa, O. V., Tuoriniemi, J. T., Nummila, K. K., Vuorinen, R. T., Clausen, K. N., Lefmann, K. & Rasmussen, F. B., 1 Apr 1996, In: Journal of Applied Physics. 79, 8, p. 5078-5080 3 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
  2 Citations (Scopus)

• Neutron experiments on nuclear order in silver at pK temperatures

  Nummila, K. K., Tuoriniemi, J. T., Vuorinen, R. T., Lounasmaa, O. V., Lefmann, K., Clausen, K. N., Metz, A., Siemensmeyer, K., Lipinski, L., Steiner, M. & Rasmussen, F. B., 1 Jan 1996, In: Czechoslovak Journal of Physics. 46, SUPPL. 4, p. 2201-2202 2 p.

  Research output: Contribution to journal › Journal article › Research › peer-review
• 1995

  Neutron Experiments on Antiferromagnetic Nuclear Order in Silver at Picokelvin Temperatures

  Tuoriniemi, J. T., Nummila, K., Vuorinen, R. T., Lounasmaa, O. V., Metz, A., Siemensmayer, K., Steiner, M., Clausen, K. N., Lefmann, K. & Rasmussen, F. B., 30 Jun 1995, In: Physical Review Letters. 75, p. 3744-3747

  Research output: Contribution to journal › Journal article › Research
  33 Citations (Scopus)
• 1994

  Foton - et fysikspil

  Oddershede, L. B., Jacobsen, R. H., Lefmann, K. & Thoft, N. B., 1 Mar 1994, In: Kvant. 4, p. 9-18

  Research output: Contribution to journal › Journal article › Communication

• Neutron scattering cross section of the S=1/2 Heisenberg triangular antiferromagnet

  Lefmann, K. & Hedegård, P., 1 Jul 1994, In: Physical Review B. Condensed Matter and Materials Physics. 50, 1047.

  Research output: Contribution to journal › Journal article › Research › peer-review

• NMR spectra of pure ¹³C diamond

  Lefmann, K., Buras, B., Pedersen, E. J., Shabanova, E. S., Thorsen, P. A., Rasmussen, F. B. & Sellschop, J. P. F., 1 Dec 1994, In: Physical Review B. 50, 15623.

  Research output: Contribution to journal › Journal article › Research › peer-review
• 1993

  Bodegadage (on the physics of billiards)

  Lefmann, K., 19 Nov 1993, In: Monthly Communication from the Faculty of Science . 2, p. 15-16

  Research output: Contribution to journal › Journal article › Communication
• 1989

  Superflydende He^-4

  Lefmann, K. & Rischel, C., 18 Nov 1989, In: Gamma. 75, p. 3-13

  Research output: Contribution to journal › Journal article › Communication