Regensburg 2019 – wissenschaftliches Programm
MA 2.7: Vortrag
Montag, 1. April 2019, 11:00–11:15, H37
tuning femtoseconds magnetization dynamics of FePt by Mn doping — •Yuting Liu1, Ute Bierbrauer1, Cinja Seick2, Moritz Hofherr1, Nataliia Safonova3, Manfred Albrecht3, Daniel Steil1, Benjamin Stadtmuller1, Stefan Mathias2, and Martin Aeschlimann1 — 1Department of Physics and Research Center OPTIMAS,University of Kaiserslautern, Germany — 2Institute of Physics, University of Gottingen, Germany — 3Institute of Physics, University of Augsburg, Germany
Understanding the ultrafast response of magnetic materials after interaction of fs light pulses provides abundant topics for fundamental science, as well as new opportunities for ultrafast manipulation of magnetization in storage devices. In this work, the ultrafast magnetization dynamics of Mn doped FePt prepared by a rapid thermal annealing (RTA) process have been studied by employing the magneto optical Kerr effect using visible as well as fs-XUV radiation. The speed of demagnetization and degree of quenching can be tailored by Mn doping. In particular, we find a local minimum of the demagnetization time constant with increasing strength of the optical excitation, i.e., with increasing laser fluence, leading to an unusual camel-like demagnetization vs. quenching curve in this material system. These results provide a prominent example in which way the implantation of magnetic impurity atoms into a magnetic host material can severely alter and manipulate the ultrafast magnetization dynamics of complex materials.