DIFFRACTION GROUP

Marie-Hélène Lemée-Cailleau				Physicist, PhD-HDR
				ILL Scientist (VIVALDI)
				College 5A "Crystallography" Secretary
				e-mail:	lemee@ill.fr
				Room:	116, ILL4
				Phone:	+33 (0)4.76.20.73.88
				FAX:	+33 (0)4.76.20.76.48
				VIVALDI:	+33 (0)4.76.20.79.33

Responsibilities

• Responsible for the Very Intense Vertical Axis Laue DIffractometer VIVALDI
• Co-responsible for the Laue Test Diffractometer for the rapid orientation of single crystals ORIENT-EXPRESS
• College 5A "Crystallography" Secretary
• Local contact for experiments in diffraction, structural crystallography and magnetism on single crystals
• PhD supervisor (partial) of M. Buron-Le Cointe (Rennes) and E. Collet (Rennes)

Research interests

• Physics of phase transitions under high pressure or out-of-equilibrium (molecular and electronic crystals, molecular multistability in condensed matter, unconventional ferroelectric properties of solids)
• Physical and Chemical Crystallography of phase transitions
• Single-Crystal Diffractometry (novel applications, position-sensitive detectors, white-beam Laue techniques, data visualisation)

Selected publications

• "Raman scattering study of the n=4 incommensurate phase of biphenyl under pressure", M.H. Lemée-Cailleau, A. Girard, H. Cailleau, Y. Délugeard, Phys. Rev B45, 12682-12690 (1992)
• "Symmetry breaking and structural changes at the neutral-to-ionic transition in TTF-chloranil", M. Le Cointe, M.H. Lemée-Cailleau, H. Cailleau, B. Toudic, G. Heger, F. Moussa, P. Schweiss, K.H. Kraft, N. Karl, Phys. Rev. B51, 3374-3386 (1995)
• "Pretransitional dynamics of structural phase transition in Anthracene-TCNB: a comparison of Raman scattering and inelastic neutron scattering experiments", P. Bourges, M.H. Lemée-Cailleau, P. Launois, C. Ecolivet, H. Cailleau, F. Moussa, A. Mierzejewski, Phys. Rev. B54, 15002-15015 (1996)
• "Thermodynamics of neutral-to-ionic transition as condensation and crystallyzation of charge-transfer excitations", M.H. Lemée-Cailleau, M. Le Cointe, H. Cailleau, T. Luty, F. Moussa, J. Roos, D. Brinkmann, B. Toudic, C. Ayache, N. Karl, Phys. Rev. Lett. 79, 1690-1693 (1997)
• "Condensation of self-trapped charge-transfer excitations and interplay between quantum and thermal effetcs at the neutral-to-ionic transition", M. Buron-Le Cointe, M.H. Lemée-Cailleau, H. Cailleau, T. Luty, J. Low Temp. Phys. 111, 677-691 (1998)
• "Singular solid-liquid-gas like phase diagramof neutral-to-ionic transition", M.H. Lemée-Cailleau, M. Buron, E. Collet, H. Cailleau, T. Luty, NATO ASI Series "High Pressure Molecular Science" Eds. R. Winter & J. Jonas (Kluwer Academic Publishers), 219-224 (1999)
• "Co-operativity at neutral-ionic transformation", H. Cailleau, E. Collet, T. Luty, M.H. Lemée-Cailleau, M. Buron-Le Cointe, S. Koshihara, NATO Science Series "Multiphonon and light driven multielectron processes in organics: new phenomena, materials and applications", Eds. F. Kajzar &V. Agranovitch, vol 3/79, 451-465 (2000)
• "Structural evidence of ferrielectric neutral-ionic layered ordering in 2,6-dimethyltetrathiafulvalene-p-chloranil", E. Collet, M. Buron-Le Cointe, M.H. Lemée-Cailleau, H. Cailleau, L. Toupet, M. Meven, S. Mattauch, G. Heger, N. Karl, Phys. Rev B, 63, 054105-1/12 (2001)
• "Direct evidence of lattice-relaxed charge-transfer exciton-strings", E. Collet, M. Buron-Le Cointe, M.H. Lemée-Cailleau, H. Cailleau, J.F. Bérar, S. Ravy, N. Karl, Europhysics Letters, 57(1) 67-73 (2002)
• "Laser-Induced Ferroelectric Structural Order in an Organic Charge-Transfer Crystal", E. Collet, M.H. Lemée-Cailleau, M. Buron-Le Cointe, H. Cailleau, M. Wulff, T. Luty, S. Koshihara, M. Meyer, L. Toupet, P. Rabiller, S. Techert, Science 300, 612-615 (2003)
• "Probing photoinduced phase transition in a charge-transfer molecular crystal by 100 picosecond x-ray diffraction", L. Guérin, E. Collet, M.H. Lemée-Cailleau, M. Buron-Le Cointe, H. Cailleau, A. Plech, M. Wulff, S. Koshihara, T. Luty, Chemical Physics Special issue: Ultrafast Science with X-rays and Electrons vol 299/2-3, 163-170 (2004)
• "Laue diffraction : the key for neutron diffraction from submillimetric-volume single crystals", M.H. Lemée-Cailleau, G.J. McIntyre, C. Wilkinson, Journal de Physique IV, 131, 335-338 (2005)
• "One-Dimensional Fluctuating Nanodomains in the Charge-Transfer Molecular System TTF-CA and their First-Order Crystallization", M. Buron-Le Cointe , M. H. Lemée-Cailleau , H. Cailleau , S. Ravy , J. F. Bérar , S. Rouzière , E. Elkaïm , and E. Collet, Phys. Rev. Lett. 96, 205503 (2006)

Curriculum Vitae

• 1986 - 1989 Ph.D. Thesis "Transitions de phase dans des cristaux moléculaires : Etude sous pression par diffusion Raman en association avec la diffusion neutronique", Department of Physics, University of Rennes 1, France
• 2003 Habilitation à Diriger les Recherches, Mention Physique "Transitions de phase dans les cristaux moléculaires : de l'équilibre thermique sous pression vers le contrôle optique", Department of Physics, University of Rennes 1, France
• 1989 - 1990 Associate Researcher at the University of Rennes 1, France
• 1990 - 2004 Research Scientist, CNRS, Rennes, France
• since 2004 ILL Physicist