@misc{MatternPudellDumesniletal.2023,
  author    = {Mattern, Maximilian and Pudell, Jan-Etienne and Dumesnil, Karine and von Reppert, Alexander and Bargheer, Matias},
  title     = {Towards shaping picosecond strain pulses via magnetostrictive transducers},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1321},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-58886},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-588868},
  pages     = {7},
  year      = {2023},
  abstract  = {Using time-resolved x-ray diffraction, we demonstrate the manipulation of the picosecond strain response of a metallic heterostructure consisting of a dysprosium (Dy) transducer and a niobium (Nb) detection layer by an external magnetic field. We utilize the first-order ferromagnetic-antiferromagnetic phase transition of the Dy layer, which provides an additional large contractive stress upon laser excitation compared to its zerofield response. This enhances the laser-induced contraction of the transducer and changes the shape of the picosecond strain pulses driven in Dy and detected within the buried Nb layer. Based on our experiment with rare-earth metals we discuss required properties for functional transducers, which may allow for novel field-control of the emitted picosecond strain pulses.},
  language  = {en}
}
@misc{ZeuschnerMatternPudelletal.2021,
  author    = {Zeuschner, Steffen Peer and Mattern, Maximilian and Pudell, Jan-Etienne and von Reppert, Alexander and R{\"o}ssle, M. and Leitenberger, Wolfram and Schwarzkopf, J. and Boschker, J. E. and Herzog, Marc and Bargheer, Matias},
  title     = {Reciprocal space slicing},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1137},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-49976},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-499761},
  pages     = {13},
  year      = {2021},
  abstract  = {An experimental technique that allows faster assessment of out-of-plane strain dynamics of thin film heterostructures via x-ray diffraction is presented. In contrast to conventional high-speed reciprocal space-mapping setups, our approach reduces the measurement time drastically due to a fixed measurement geometry with a position-sensitive detector. This means that neither the incident (ω) nor the exit (2θ) diffraction angle is scanned during the strain assessment via x-ray diffraction. Shifts of diffraction peaks on the fixed x-ray area detector originate from an out-of-plane strain within the sample. Quantitative strain assessment requires the determination of a factor relating the observed shift to the change in the reciprocal lattice vector. The factor depends only on the widths of the peak along certain directions in reciprocal space, the diffraction angle of the studied reflection, and the resolution of the instrumental setup. We provide a full theoretical explanation and exemplify the concept with picosecond strain dynamics of a thin layer of NbO2.},
  language  = {en}
}
@misc{MatternPudellLaskinetal.2021,
  author    = {Mattern, Maximilian and Pudell, Jan-Etienne and Laskin, G. and von Reppert, Alexander and Bargheer, Matias},
  title     = {Analysis of the temperature- and fluence-dependent magnetic stress in laser-excited SrRuO3},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51571},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-515718},
  pages     = {11},
  year      = {2021},
  abstract  = {We use ultrafast x-ray diffraction to investigate the effect of expansive phononic and contractive magnetic stress driving the picosecond strain response of a metallic perovskite SrRuO3 thin film upon femtosecond laser excitation. We exemplify how the anisotropic bulk equilibrium thermal expansion can be used to predict the response of the thin film to ultrafast deposition of energy. It is key to consider that the laterally homogeneous laser excitation changes the strain response compared to the near-equilibrium thermal expansion because the balanced in-plane stresses suppress the Poisson stress on the picosecond timescale. We find a very large negative Gr{\"u}neisen constant describing the large contractive stress imposed by a small amount of energy in the spin system. The temperature and fluence dependence of the strain response for a double-pulse excitation scheme demonstrates the saturation of the magnetic stress in the high-fluence regime.},
  language  = {en}
}
@misc{vonReppertMatternPudelletal.2020,
  author    = {von Reppert, Alexander and Mattern, Maximilian and Pudell, Jan-Etienne and Zeuschner, Steffen Peer and Dumesnil, Karine and Bargheer, Matias},
  title     = {Unconventional picosecond strain pulses resulting from the saturation of magnetic stress within a photoexcited rare earth layer},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  number    = {899},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-46935},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-469350},
  pages     = {15},
  year      = {2020},
  abstract  = {Optical excitation of spin-ordered rare earth metals triggers a complex response of the crystal lattice since expansive stresses from electron and phonon excitations compete with a contractive stress induced by spin disorder. Using ultrafast x-ray diffraction experiments, we study the layer specific strain response of a dysprosium film within a metallic heterostructure upon femtosecond laser-excitation. The elastic and diffusive transport of energy to an adjacent, non-excited detection layer clearly separates the contributions of strain pulses and thermal excitations in the time domain. We find that energy transfer processes to magnetic excitations significantly modify the observed conventional bipolar strain wave into a unipolar pulse. By modeling the spin system as a saturable energy reservoir that generates substantial contractive stress on ultrafast timescales, we can reproduce the observed strain response and estimate the time- and space dependent magnetic stress. The saturation of the magnetic stress contribution yields a non-monotonous total stress within the nanolayer, which leads to unconventional picosecond strain pulses.},
  language  = {en}
}