Temperature, wavelength, and polarization dependent time resolved optical spectroscopy of half-metallic CrO2 -: art. no. 10C309

CrO2 is an important transition metal oxide due to its half-metallic behavior. We have performed ultrafast laser pump-probe differential transmission experiments on epitaxial CrO2(110)Polarizations parallel and perpendicular to the c axis were used, at wavelengths corresponding to important magnetic excitations: 1300 (1 eV), 800 (1.5 eV), and 650 nm (2 eV). Anisotropy is observed in the polarization-dependent measurements and is attributed to the electronic orbital anisotropy. A critical change of transient transmission is also observed at the Curie temperature of 386 K. This behavior reveals the close relationship between the optical absorption and the spin dynamics of this material. (c) 2005 American Institute of Physics.