Michael Leitner | Technische Universität München

Research interests

My main point of scientific interest is dynamics in hard condensed matter. Recently I have been occupying myself primarily with Heusler alloys, specifically in systems derived from or related to the Ni₂MnZ family. Due to the convenient relation of ordering transition temperatures and kinetics in these systems, the effect of order on aspects of magnetism and martensitic transitions can be studied.
Further, I am closely collaborating with a local group on questions of the electronic structure in solids, specifically the Fermi surface, which we are studying via Angular Correlation of Positron Annihilation Radiation (ACPAR). For an account of the method with special emphasis on the mathematics of data treatment see my mathematics diploma thesis.
My previous working group applies several methods of measurement for studying diffusion on the atomic scale. I was responsible for implementing X-ray photon correlation spectroscopy (XPCS), which relates the temporal fluctuations of the scattered intensity of coherent synchrotron radiation to the dynamics in the investigated sample. We have applied this method successfully for determining the jump mechanism in a Cu-Au alloy. The level of the method is still adequately described in my doctoral thesis of 2010.
Also I am involved in a quite successful (see here) collaboration with a group of biologists from the Austrian Umweltbundesamt and VINCA. Here our aim is to understand and predict the spread of invasive plants, with Ambrosia Artemisiifolia (the common ragweed), a highly allergenic plant, as a concrete example.

Publications

Articles in peer-reviewed journals

J. Ketels, M. Leitner, P. Böni, Ch. Hugenschmidt, M. Sekania, A. D. N. James, J. A. E. Bonart, N. Unglert, and L. Chioncel, ''Fermi Surface Modeling of Light-Rare-Earth Hexaborides using Positron Annihilation Spectroscopy'', phys. stat. sol. B 259, 2100151 (2021).
P. Neibecker, X. Xu, D. Simonne, L. Hollender, F. Porcher, A. Senyshyn, T. Omori, R. Kainuma, W. Petry, and M. Leitner, ''Atomic Order along the Half- to Full-Heusler Transition in Ni_1+xMnSb'', phys. stat. sol. B 259, 2100174 (2021).
U. Zweck and M. Leitner, ''Antiphase domain growth: Correlation functions and structure factors in the scaling regime'', Phys. Rev. B 104, 094101 (2021).
J. Ketels, D. Billington, S. B. Dugdale, M. Leitner, and Ch. P. Hugenschmidt, ''Momentum density spectroscopy of Pd: Comparison of 2D-ACAR and Compton scattering using a 1D-to-2D reconstruction method'', Phys. Rev. B 104, 075160 (2021).
Ch. Tietz, T. M. Fritz, K. Holzweber, M. Legenstein, B. Sepiol, and M. Leitner, ''Diffusive dynamics in an amorphous superionic conductor'', Phys. Rev. Research 2, 043141 (2020).
L. Mathes, Th. Gigl, M. Leitner, and Ch. Hugenschmidt, ''Breakdown of Arrhenius law of temperature-dependent vacancy concentration in fcc lanthanum'', Phys. Rev. B 101, 134105 (2020).
K. Holzweber, Ch. Tietz, T. M. Fritz, B. Sepiol, and M. Leitner, ''Beam-induced atomic motion in alkali borate glasses'', Phys. Rev. B 100, 214305 (2019).
A. Glensk, B. Grabowski, T. Hickel, J. Neugebauer, J. Neuhaus, K. Hradil, W. Petry, and M. Leitner, ''Phonon Lifetimes throughout the Brillouin Zone at Elevated Temperatures from Experiment and Ab Initio'', Phys. Rev. Lett. 123, 235501 (2019).
P. Neibecker, M. E. Gruner, X. Xu, R. Kainuma, W. Petry, R. Pentcheva, and M. Leitner, ''Ordering tendencies and electronic properties in quaternary Heusler derivatives'', Phys. Rev. B 96, 165131 (2017).
P. Neibecker, M. Leitner, M. Kushaim, T. Boll, D. Anjum, T. Al-Kassab, and F. Haider, ''L1₂ ordering and δ' precipitation in Al-Cu-Li'', Sci. Rep. 7, 3254 (2017).
J. A. Weber, D. Benea, W. H. Appelt, H. Ceeh, W. Kreuzpaintner, M. Leitner, D. Vollhardt, Ch. Hugenschmidt, and L. Chioncel, ''Electronic correlations in vanadium revealed by electron-positron annihilation measurements'', Phys. Rev. B 95, 075119 (2017).
M. Stana, B. Sepiol, R. Kozubski, and M. Leitner, ''Chemical ordering beyond the superstructure in long-range ordered systems'', New J. Phys. 18, 113051 (2016).
M. Reiner, A. Bauer, M. Leitner, Th. Gigl, W. Anwand, M. Butterling, A. Wagner, P. Kudejova, Ch. Pfleiderer, and Ch. Hugenschmidt, ''Positron spectroscopy of point defects in the skyrmion-lattice compound MnSi'', Sci. Rep. 6, 29109 (2016).
M. Leitner, J. A. Weber, and H. Ceeh, ''Fermi surface determination from momentum density projections'', New J. Phys. 18, 063033 (2016).
K. Hülber, J. Wessely, A. Gattringer, D. Moser, M. Kuttner, F. Essl, M. Leitner, M. Winkler, S. Ertl, W. Willner, I. Kleinbauer, N. Sauberer, Th. Mang, N. E. Zimmermann, and S. Dullinger, ''Uncertainty in predicting range dynamics of endemic alpine plants under climate warming'', Glob. Change Biol. 22, 2608 (2016).
H. Ceeh, J. A. Weber, P. Böni, M. Leitner, D. Benea, L. Chioncel, H. Ebert, J. Minár, D. Vollhardt, and Ch. Hugenschmidt, ''Local electron-electron interaction strength in ferromagnetic nickel determined by spin-polarized positron annihilation'', Sci. Rep. 6, 20898 (2016).
J. A. Weber, A. Bauer, P. Böni, H. Ceeh, S. B. Dugdale, D. Ernsting, W. Kreuzpaintner, M. Leitner, Ch. Pfleiderer, and Ch. Hugenschmidt, ''Spin-Resolved Fermi Surface of the Localized Ferromagnetic Heusler Compound Cu₂MnAl Measured with Spin-Polarized Positron Annihilation'', Phys. Rev. Lett. 115, 206404 (2015).
S. Dullinger, N. Dendoncker, A. Gattringer, M. Leitner, Th. Mang, D. Moser, C. A. Mücher, Ch. Plutzar, M. Rounsevell, W. Willner, N. E. Zimmermann, and K. Hülber, ''Modelling the effect of habitat fragmentation on climate-driven migration of European forest understorey plants'', Div. Distrib. 21, 1375 (2015).
F. Essl, K. Biró, D. Brandes, O. Brönnimann, J. M. Bullock, D. S. Chapman, B. Chauvel, S. Dullinger, B. Fumanal, A. Guisan, G. Karrer, G. Kazinczi, Ch. Küffer, B. Laitung, C. Lavoie, M. Leitner, Th. Mang, D. Moser, H. Müller-Schärer, B. Petitpierre, R. Richter, U. Schaffner, M. Smith, U. Starfinger, R. Vautard, G. Vogl, M. von der Lippe, and S. Follak, ''Biological Flora of the British Isles: Ambrosia artemisiifolia'', J. Ecol. 103, 1069 (2015).
P. Neibecker, M. Leitner, G. Benka, and W. Petry, ''Increasing the achievable state of order in Ni-based Heusler alloys via quenched-in vacancies'', Appl. Phys. Lett. 105, 261904 (2014).
M. Ross, M. Stana, M. Leitner, and B. Sepiol, ''Direct observation of atomic network migration in glass'', New J. Phys. 16, 093042 (2014).
J. Neuhaus, M. Leitner, K. Nicolaus, W. Petry, B. Hennion, and A. Hiess, ''Role of vibrational entropy in the stabilization of the high-temperature phases of iron'', Phys. Rev. B 89, 184302 (2014).
M. Leitner and A. Mikikits-Leitner, ''Nonlinear differential identities for cnoidal waves'', Math. Nachr. 287, 2040 (2014).
S. Ener, T. Mehaddene, B. Pedersen, M. Leitner, J. Neuhaus, and W. Petry, ''Vibrational properties of Ni–Mn–Ga shape memory alloy in the martensite phases'', New J. Phys. 15, 123016 (2013).
R. Richter, U. E. Berger, S. Dullinger, F. Essl, M. Leitner, M. Smith and G. Vogl, ''Spread of invasive ragweed: climate change, management and how to reduce allergy costs'', J. Appl. Ecol. 50, 1422 (2013).
H. Ceeh, J. A. Weber, M. Leitner, P. Böni, and Ch. Hugenschmidt, ''The source-sample stage of the new two-dimensional angular correlation of annihilation radiation spectrometer at Technische Universität München'', Rev. Sci. Instrum. 84, 043905 (2013).
M. Stana, M. Leitner, M. Ross, and B. Sepiol, ''Studies of atomic diffusion in Ni-Pt solid solution by x-ray photon correlation spectroscopy'', J. Phys.: Condens. Matter 25, 065401 (2013).
R. Richter, S. Dullinger, F. Essl, M. Leitner, and G. Vogl, ''How to account for habitat suitability in weed management programmes?'', Biol. Inv. 15, 657 (2013).
M. Leitner, H. Ceeh, and J.-A. Weber, ''Eliminating spatial distortions in Anger-type gamma cameras'', New J. Phys. 14, 123014 (2012).
M. Leitner, ''Absence of a trapping effect on the kinetic critical radius in nucleation and growth processes'', Acta. Mat. 60, 6779 (2012).
M. Leitner, B. Sepiol, L.-M. Stadler, and B. Pfau, ''Time-resolved study of the crystallization dynamics in a metallic glass'', Phys. Rev. B 86, 064202 (2012).
S. Dullinger, A. Gattringer, W. Thuiller, D. Moser, N. E. Zimmermann, A. Guisan, W. Willner, Ch. Plutzar, M. Leitner, Th. Mang, M. Caccianiga, T. Dirnböck, S. Ertl, A. Fischer, J. Lenoir, J.-Ch. Svenning, A. Psomas, D. R. Schmatz, U. Silc, P. Vittoz, and K. Hülber, ''Extinction debt of high-mountain plants under twenty-first-century climate change'', Nature Clim. Change 2, 619 (2012).
F. Gröstlinger, M. Rennhofer, M. Leitner, E. Partyka-Jankowska, B. Sepiol, B. Laenens, N. Planckaert, and A. Vantomme, ''Anisotropic diffusion in FePt thin films'', Phys. Rev. B 85, 134302 (2012).
M. Leitner and G. Vogl, ''Quasi-elastic scattering under short-range order: the linear regime and beyond'', J. Phys.: Condens. Matter 23, 254206 (2011).
S. Dullinger, Th. Mang, T. Dirnböck, S. Ertl, A. Gattringer, G. Grabherr, M. Leitner, and K. Hülber, ''Patch configuration affects alpine plant distribution'', Ecography 34, 576 (2011).
A. Mikikits-Leitner, B. Sepiol, M. Leitner, J. Cieślak, and S. Dubiel, ''Nucleation mechanism of the σ-to-α phase transition in Fe_1-xCr_x'', Phys. Rev. B 82, 100101(R) (2010).
M. G. Smolik, S. Dullinger, F. Essl, I. Kleinbauer, M. Leitner, J. Peterseil, L.-M. Stadler, and G. Vogl, ''Integrating species distribution models and interacting particle systems to predict the spread of an invasive alien plant'', J. Biogeogr. 37, 411 (2010).
M. Leitner, B. Sepiol, L.-M. Stadler, B. Pfau, and G. Vogl, ''Atomic diffusion studied with coherent X-rays'', Nature Mat. 8, 717 (2009).
M. Leitner, H. Peterlik, B. Sepiol, H. Graener, M. Beleites, and G. Seifert, ''Uniformly oriented, ellipsoidal nanovoids in glass created by electric-field-assisted dissolution of metallic nanoparticles'', Phys. Rev. B 79, 153408 (2009).

Articles in peer-reviewed conference special issues

J. A. Weber, P. Böni, H. Ceeh, M. Leitner, and Ch. Hugenschmidt, ''The effect of regularization on the reconstruction of ACAR data'', J. Phys. Conf. Ser. 505, 012047 (2014).
H. Ceeh, J. A. Weber, Ch. Hugenschmidt, M. Leitner, and P. Böni, ''Positron beam optics for the 2D-ACAR spectrometer at the NEPOMUC beamline'', J. Phys. Conf. Ser. 505, 012041 (2014).
H. Ceeh, J. A. Weber, Ch. Hugenschmidt, M. Leitner, and P. Böni, ''First measurements with the Munich 2D-ACAR spectrometer on Cr'', J. Phys. Conf. Ser. 443, 012094 (2013).
J. A. Weber, P. Böni, H. Ceeh, M. Leitner, and Ch. Hugenschmidt, ''First 2D-ACAR Measurements on Cu with the new Spectrometer at TUM'', J. Phys. Conf. Ser. 443, 012092 (2013).
G. Vogl, M. Smolik, L.-M. Stadler, M. Leitner, F. Essl, S. Dullinger, I. Kleinbauer, and J. Peterseil, ''Modelling the spread of ragweed: Effects of habitat, climate change and diffusion'', Eur. Phys. J. Special Topics 161, 167 (2008).

Books and book contributions

M. Leitner and I. Kühn, ''Dispersal in Plants and Animals'', in ''Diffusive Spreading in Nature, Technology and Society'' edited by A. Bunde, J. Caro, J. Kärger, and G. Vogl, Springer (Cham 2018).
M. Leitner, ''Studying Atomic Dynamics with Coherent X-rays'', Springer (Berlin, Heidelberg 2012).
M. Leitner, S. Dullinger, F. Essl, and G. Vogl, ''The Spread of Ragweed as a Diffusion Process'', in ''Migrations: Interdisciplinary Perspectives'' edited by M. Messer, R. Schroeder, and R. Wodak, Springer (Wien, Heidelberg 2012).

Theses

M. Leitner, Electron momentum reconstruction in ACPAR, mathematics diploma thesis, University of Vienna, 2013.
M. Leitner, Studying Atomic Dynamics with Coherent X-rays, physics doctoral thesis, University of Vienna, 2010.
M. Leitner, Diffusion studies with X-ray photon correlation spectroscopy, physics diploma thesis, University of Vienna, 2007.

Talks

Invited talks at institutes

''Oscillatory dynamics in simple systems at elevated temperatures — beyond a perturbational treatment of anharmonicity'', Institut für Materialwissenschaft, Universität Stuttgart, 6 July 2020, Stuttgart, Germany.
''Atomic Diffusion studied by Coherent X-ray Scattering'', Fakultät für Physik, Universität Wien, 20 November 2018, Vienna, Austria.
''Experimental determination of vibrational dynamics in the solid state'', MPI Eisenforschung, 4 April 2017, Düsseldorf, Germany.
''Measuring Atomic Dynamics by Coherent X-ray Scattering'', DESY, 20 February 2014, Hamburg, Germany.
''Following atomic dynamics using coherent X-rays'', Forschungs-Neutronenquelle Heinz Maier-Leibnitz, 20 April 2011, Garching bei München, Germany.
''SAXS characterization of silver nanoparticles in glass'', Institut für Physik/Optik, Naturwissenschaftliche Fakultät II, Martin-Luther-Universtität Halle-Wittenberg, 2 July 2007, Halle/Saale, Germany.

Invited talks at conferences

''Polycrystalline time-of-flight inelastic neutron scattering beyond the density of states'', dyProSo XXXVII, 8−12 September 2019, Ferrara, Italy.
''Atomic diffusion studied by coherent X-ray scattering'', Diffusion Fundamentals VIII, 1−5 September 2019, Erlangen, Germany.
''Dispersal in Plants and Animals: Modelling'', Diffusion Fundamentals VI, 23−26 August 2015, Dresden, Germany.
''Following atomic dynamics using coherent X-rays'', Coherence 2010, International Workshop on Phase Retrieval and Coherent Scattering, 8−11 June 2010, Warnemünde, Germany.
''Probing dynamics in alloys by coherent scattering'', 5th International Conference on Diffusion in Solids and Liquids DSL 2009, 24−26 June 2009, Rome, Italy.
''Atom jumps studied by coherent synchrotron radiation'', 7th International Conference on Diffusion in Materials DIMAT 2008, 28−31 October 2008, Lanzarote, Canary Islands.

Contributed talks at conferences and public workshops

''Oscillatory dynamics in simple systems at elevated temperatures --- beyond a perturbational treatment of anharmonicity'', dyProSo XXXVIII, 8 September 2021, Luxembourg, Luxembourg.
''Oscillatory dynamics in simple systems at elevated temperatures --- beyond a perturbational treatment of anharmonicity'', Joint Annual Meeting of ÖPG and SPS, 3 September 2021, Innsbruck, Austria.
''Anharmonic phonons at elevated temperatures in Al: experiment and ab initio predictions'', 5th Workshop on ab initio phonon calculations, 3 December 2019, Krakow, Poland.
''A microscopic model of spatio-temporal language dynamics'', DPG spring meeting, 1 April 2019, Regensburg, Germany.
''Premartensite in Ni₂MnAl_0.5Ga_0.5'', ESOMAT 2018, 30 August 2018, Metz, France.
''Continuous transition from antiferro- to ferromagnetic state via moment canting in Ni_2-xCo_xMnAl'', DPG spring meeting, 12 March 2018, Berlin, Germany.
''Spatio-temporal dynamics of the cholera epidemic of 1831/1832 in Austria'', DPG spring meeting, 17 March 2015, Berlin, Germany.
''Thermodynamics of point defects and diffusion mechanisms in B2-ordered compounds'', DPG spring meeting, 16 March 2015, Berlin, Germany.
''Temperature-dependent phonons in Fe: Implications on thermodynamics and diffusion'', dyProSo XXXIV, 15−19 September 2013, Vienna, Austria.
''The role of phonons in the thermodynamics of Fe'', DPG spring meeting, 14 March 2013, Regensburg, Germany.
''Studying atomic diffusion by coherent synchrotron radiation'', ÖPG-Tagung 2010, 6−10 September 2010, Salzburg, Austria.
''Atomic jumps studied by coherent synchrotron radiation'', DPG spring meeting, 24 March 2009, Dresden, Germany.
''Messung atomarer Diffusion mittels Röntgenkorrelationsspektroskopie'', ÖPG-Tagung 2008, 22−26 September 2008, Leoben, Austria.
''Measuring atomic diffusion in crystalline solids with XPCS'', 2nd XPCS-XFEL Consortium Meeting, 26 March 2008, Hamburg, Germany.
''Bewegung einzelner Atome im Blitzlicht des XFEL'', Treffen der österreichischen Nutzer von Synchrotronstrahlung, Bundesministerium für Wissenschaft und Forschung, 25 February 2008, Vienna, Austria.
''SAXS characterization of silver nanoparticles in glass'', DPG spring meeting, 29 March 2007, Regensburg, Germany.