Parts | Days | Selection | Search | Updates | Downloads | Help
DY: Fachverband Dynamik und Statistische Physik
DY 60: Critical Phenomena and Phase Transitions
DY 60.4: Talk
Friday, March 13, 2026, 10:15–10:30, ZEU/0114
Experimental study of dynamic phase transitions in nearly isotropic ferromagnetic films — Juan Marcos Marin Ramirez, Luciano Bravo, and •Andreas Berger — CIC nanoGUNE BRTA, E-20018 Donostia-San Sebastián, Spain
Non-equilibrium phase transitions occur across a wide range of physical systems. A relevant example is the dynamic phase transition (DPT) in ferromagnets, where the time-averaged magnetization Q, the dynamic order parameter, changes sharply under an oscillating field as its amplitude H0 or period P vary. Hereby, it has also been observed that Q is dependent on the presence of an additional bias field Hb, which turns out to be the conjugate field of Q. Studies of the DPT have yielded important insights into dynamically ordered systems, their phase-space behaviour, and transient properties [1], yet this work has focused almost exclusively on Ising-type systems, restricting our understanding to a single material class [2]. Here, we experimentally investigate the DPT in polycrystalline Co films with very weak anisotropy. Dynamic magnetic states are monitored via real-time magneto-optical Kerr effect measurements across the relevant dynamic phase space. We find that the qualitative features of the dynamic phase diagram closely follow those of uniaxial Ising-type films. However, the metamagnetic anomalies of the paramagnetic dynamic state, ubiquitous in Ising-type films, appear to be significantly weaker in our nearly isotropic films. [1] P. Riego et al., Phys. B Condens. Matter 549, 13 (2018). [2] M. Quintana and A. Berger, Phys. Rev. Lett. 131, 116701 (2023).
Keywords: Magnetization dynamics; Dynamic phase transitions; Isotropic thin films