Föreläsning: Controlling magnetodynamics in a perovskite systems - structure and interface effects in La0.7Sr0.3MnO3 thin films on SrTiO3

  • Datum: –14.00
  • Plats: Ångströmlaboratoriet Beurlingrummet
  • Föreläsare: Erik Wahlström, NTNU
  • Kontaktperson: Björgvin Hjörvarsson
  • Föreläsning

LSMO (La0.7Sr0.3MnO3), a prototypical manganite oxide, has attracted a lot of interest during the last decades due to it´s high Curie temperature (~370 K), high spin polarization and the existence of colossal magnetoresistance within the material. In spite of these interesting properties, the material has found little use in device structures, presumably due to the problems of interfacing the material and maintaining bulk properties for very thin layers.

From a magnetodynamic point of view, La0.7Sr0.3MnO3 films have been shown to provide both low damping and well defined resonance lines that are prerequisites for using the material in devices. However, much remains to be understood concerning resonant mode structure, the thickness and structure dependence of the resonance lines and their damping that is important for device implementation. Here, I will present a comprehensive study of the dynamic magnetic properties of La0.7Sr0.3MnO3/SrTiO3 thin films Where the main focus will be on how the interfaces, domain structure, and thickness affect dynamic properties. The presentation is based on a series of experiments from films grown using pulsed laser deposition [1-4], in a thickness range from 4 to 150 unit cells (UC) utilizing different substrates, characterized  through ferromagnetic resonance (FMR) and static magnetometry and photoelectron spectroscopy (UPS/XPS) at variable temperature.

1. Singh S., Bolstad T., Hallsteinsen I., Tybell T. and Wahlström E., Magneto-dynamic properties of complex oxide - La0.7Sr0.3MnO3/SrTiO3 - heterostructure interface. Applied Physics Letters (accepted).

2. Wahlström, E., et al., Twinned-domain-induced magnonic modes in epitaxial LSMO/STO films. New Journal of Physics, 2017. 19(6).

3. Flovik, V., et al., Thickness and temperature dependence of the magnetodynamic damping of pulsed laser deposited La0.7Sr0.3MnO3 on (111)-oriented SrTiO3. Journal of Magnetism and Magnetic Materials, 2016. 420: p. 280-284.

4. Monsen Å., B.J.E., Macia F., Wells J.J., Nordblad P., Kent A., Mathieu R., Tybell T. Wahlström E., Thickness dependence of dynamic and static magnetic properties of pulsed laser deposited La0.7Sr0.3MnO3 films on SrTiO3(001). JMMM, 2014. 369: p. 197.