Ultrafast photogeneration and photodetection of coherent acoustic phonons in ferroelectric BiFeO3 Mariusz Lejman To cite this version: Mariusz Lejman. Ultrafast photogeneration and photodetection of coherent acoustic phonons in fer- roelectric BiFeO3. Materials Science [cond-mat.mtrl-sci]. Université du Maine, 2015. English. NNT : 2015LEMA1015. tel-01299211 HAL Id: tel-01299211 https://tel.archives-ouvertes.fr/tel-01299211 Submitted on 7 Apr 2016 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Mariusz LEJMAN Mémoire présenté en vue de l’obtention du grade de Docteur de l’Université du Maine sous le label de L’Université Nantes Angers Le Mans École doctorale : 3MPL Discipline : Physique Unité de recherche : Institut des Molécules et Matériaux du Mans, UMR 6283 CNRS Soutenue le 06.10.15 Ultrafast Photogeneration and Photodetection of Coherent Acoustic Phonons in Ferroelectric BiFeO3 JURY Rapporteurs : Matias BARGHEER, Professor, Potsdam University, Germany Bernard PERRIN, CNRS research director, INSP-Univ. Pierre et Marie Curie Examinateurs : Jens KREISEL, CNRS research director, LIST, Luxembourg Davide BOSCHETTO, Professor, LOA-Ecole Polytechnique, Palaiseau Invité(s) : Brahim DKHIL, Professor, SPMS-CNRS, Centrale-Supelec Directeur de Thèse : Pascal RUELLO, Professor, IMMM-CNRS, Maine University Co-directeur de Thèse : Vitali GUSEV, Professor, LAUM-CNRS, Maine University Co-superviseur de Thèse : Gwenaëlle VAUDEL, Research Engineer, IMMM-CNRS, Maine University 1 2 Acknowledgements First of all I would like to express my gratitude to my PhD director Prof. Pascal Ruello. I’m very glad for his support and guidance during all my thesis. I would like to thank to Prof. Ruello for inspiring scientific discussions and substantive advice in order to improve my work. I would also like to thank a lot to co-director of my PhD Prof. Vitaly Gussev for his valuable advices during my PhD and very reasonable look at all scientific issues connected to my topic. Finally I would like to thank to my PhD co-supervisor Gwenaelle Vaudel for support in the laboratory and important assistance in the implementation of complex pump-probe experiment. Subsequently I would like to express my gratitude to our collaborators Ingrid Canero Infante and Brahim Dkhil from Ecole Centrale Paris for preparation and preliminary characterization of great samples. I would also like to thank to Mathieu Edely for devoted time and help in adaptation of some important samples for experiment as well as to Prof. Alain Bulou, Thomas Pezeril and Vasily Temnov for valuable scientific advices and discussions. In the next, I would like to thank to my colleagues and friends, especially Sergey Nikitin and Victor Shalagaskyi for free scientific discusstions and also Ievgienilia Chaban and Tymur Parpiiev for some company during PhD adventure. I would like to especially thank to my friend Alla Abramova, I could always rely on her help and support. I would also like to thank to other people who have contributed to my PhD and to my friends not mentioned here. Finally I’m very grateful to my mother for her support in difficult moments. I would like to dedicate this work to my mother, to my sweetheart and to my little son Filip, who strongly motivated me to work hard and with whom I could not always be in the important moments of their lives. 3 4 Chapter 1 Introduction ................................................. 9 Chapter 2 : Ultrafast acoustics, ultrafast phononics ........................... 13 2.1 Introduction .................................................................................................................................... 15 2.2 Principle of ultrafast acoustics, ultrafast phononics ....................................................................... 15 2.2.1 Generalities about ultrafast acoustics ...................................................................................... 15 2.3. Generation mechanisms of high frequency phonons by pulsed lasers .......................................... 19 2.3.1. Thermoelasticity (TE) ............................................................................................................... 19 2.3.2. Deformation potential (DP) ..................................................................................................... 22 2.3.3. Inverse piezoelectricity (PE) ..................................................................................................... 24 2.3.4. Electrostriction (ES). ................................................................................................................ 26 2.4. Why ferroelectrics/multiferroics for ultrafast acoustics? .............................................................. 27 2.4.1. Introduction ............................................................................................................................. 27 2.4.2. Basics of piezoelectricity and ferroelectricity .......................................................................... 28 2.4.3. Structure and general properties of bismuth ferrite (BFO) ...................................................... 31 Chapter 3 : Generation and detection of coherent acoustic phonons in BiFeO3. ....... 37 3.1 Introduction .................................................................................................................................... 39 3.2. Literature survey : Ultrafast electron and phonon dynamics and ultrafast strain in BFO .............. 39 3.2.1. Study of ultrafast electron dynamics in BFO ........................................................................... 39 3.2.2. Study of ultrafast photoinduced strain in BFO ........................................................................ 44 3.3. Results : Ultrafast light‐induced tunable LA and TA phonons source in BFO at room temperature .............................................................................................................................................................. 54 3.3.1. Sample preparation and characterization ............................................................................... 54 3.3.2. Photoinduced coherent shear and longitudinal strain in specific orientations of BFO grains at GHz frequency. .................................................................................................................................. 57 3.4. Results : Role of magnetic ordering on the photogeneration and photodetection of coherent acoustic phonon in BFO ( high temperature investigation ) ................................................................. 78 3.4.1. Experimental conditions and procedure .................................................................................. 79 3.4.2. Effect of temperature variation on generation and detection of acoustic phonons in ferroelectric BFO ............................................................................................................................... 79 3.5 Conclusion ....................................................................................................................................... 86 Chapter 4 : Ultrafast mode conversion of light induced by coherent phonons in birefringent media ................................................... 87 4.1. Introduction ................................................................................................................................... 89 4.2. Theory ............................................................................................................................................ 89 4.3. Ultrafast mode conversion of light induced by coherent phonons in ferroelectric BFO ............... 94 4.4. Ultrafast mode conversion of light induced by coherent phonons in ferroelectric lithium niobate (LNO) ..................................................................................................................................................... 99 4.4. Detection of LA phonons in birefringent crystal of calcite (CaCO3) ............................................. 112 4.5. Calculations of detected light intensity changes by different scattering processes in simple geometries .......................................................................................................................................... 116 4.6 Conclusion ..................................................................................................................................... 120 Chapter 5. General Conclusion and perspectives ................... 121 Appendix 1 : Pump‐probe setup characteristics .................... 127 Appendix 2 : Grain orientation probed by optical birefringence ... 131 5 Appendix 3 : Mode conversion in calcite axis oriented at 45 degrees versus surface (rotation of photo‐elestic tensor by 45 degrees) .. 134 Bibliography ....................................................... 137 6 7 8 Chapter 1 Introduction 9 10 Ultrafast science is the study of physical phenomena and processes that occur on very short time scales ranging from attoseconds to picoseconds