Magnetocrystalline anisotropy and spin-wave stiffness in tensilestrained La_(0.67)Ba_(0.33)MnO_3 fil

• 作 者: DUANMU QingYong TONG Wei YANG Lei HAO Lin ZHANG ZhongFeng WANG XiaoPing ZHU Hong
• 机 构: Department of Physics,University of Science and Technology of China,High Magnetic Field Laboratory,C
• 出 处: Chinese Science Bulletin
• 发表日期: 2013年33期
• 关键词: ferromagnetic Ba anisotropy epitaxial strained tensile paramagnetic sputtering m

Tensile-strained epitaxial La0.67Ba0.33MnO3(LBMO)film has been prepared by magnetron sputtering technique on(001)oriented spinel MgAl2O4substrate.The transport and magnetic measurements give an insulator-metal transition and paramagnetic-ferromagnetic transition occurring at~150 K and 250 K respectively,which implies the phase separation in such a tensile-strained film.By analyzing the angular and temperature dependences of the ferromagnetic resonance(FMR),we determine the magnetocrystalline anisotropy of the film.It is found that the tensile-strained film is dominated by an easy-axis corresponding to the compressive out-of-plane direction,though the magnitudes of anisotropy constants are relatively small and their temperature dependences are some complex.Furthermore,the FMR spectra show additional spin wave resonance(SWR),and the field positions can be indexed to follow a linear dependence on the square of index n.The scaling gives a spin-wave exchange stiffness D of 20.7 meV 2at low temperature,which is less than half of that in strain-free LBMO films,implying that the double exchange interaction is remarkably suppressed in the tensile-strained LBMO films.

Tensile-strained epitaxial La0.67Ba0.33MnO3 (LBMO) film has been prepared by magnetron sputtering technique on (001) oriented spinel MgAl2O4substrate. The transport and magnetic measurements give an insulator-metal transition and paramagnetic-ferromagnetic transition occurring at ~ 150K and 250 K respectively, which implies the phase separation in such a tensile-strained film.By analyzing the angular and temperature dependences of the ferromagnetic resonance (FMR), we determine the magnetocrystalline anisotropy of the film. It is found that the tensile-strained film is dominated by an easy-axis corresponding to the compressive out-of-plane direction, though the magnitudes of anisotropy constants are relatively small and their temperature dependences are some complex. Morerther, the FMR spectra show additional spin wave resonance (SWR), and the field positions can be indexed to follow a linear dependence on the square of index n. scaling gives a spin-wave exchange stiffness D of 20.7 meV 2at low temperature, which is less than half of that in strain-free LBMO films, implying that the double exchange interaction is remarkably suppressed in the tensile-strained LBMO films.