Ultrafast optical destruction of antiferromagnetic order in FeBO/sub 3/

Summary form only given The fundamental and practical restrictions on ultrafast magnetization dynamics is a greatly challenging area of physics of magnetism and a subject of vital importance for nowadays electronics. We have studied the dynamics of the phase transition from antiferromagnetic (afm) to paramagnetic (pm) state in FeBO/sub 3/ by pump and probe measurements of the magneto-optical Faraday effect with subpicosecond resolution. The measurements were done at the photon energy of 1.5 eV, where the mechanism of the ultrafast light-induced heating of the lattice is efficient. The Faraday rotation as a function of delay time between pump and probe pulses is shown for different bias temperatures of the sample. One can see that the dynamical changes of the Faraday effect are smaller at lower sample temperatures, while at T/sub bias/=346.5 K the pump-induced dynamical changes are larger and the Faraday rotation decreases dramatically.