Magnetic ultrathin films were fabricated layer-by-layer using a self-assembly method through the electrostatic interaction between the photosensitive diazoresin (DR) and the negatively charged Fe 3O 4 nanoparticles (N...Magnetic ultrathin films were fabricated layer-by-layer using a self-assembly method through the electrostatic interaction between the photosensitive diazoresin (DR) and the negatively charged Fe 3O 4 nanoparticles (NP-Fe 3O 4).The results of the UV-vis spectra and AFM show that the assembly of DR and NP-Fe 3O 4 is very successful.After UV irradiation,the ionic bonds of the DR/NP-Fe 3O 4 film convert to covalent ones and the magnetic films become very stable toward polar solvents.The magnetic film images with good resolution are obtained by means of selective UV-exposure of the film under a photo-mask and then developing the exposed film in the saturated aqueous solution of sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB),respectively.展开更多
Co−TiO2 nanocomposite films were prepared via magnetron sputtering at various substrate temperatures.The films comprise Co particles dispersed in an amorphous TiO2 matrix and exhibit coexisting ferromagnetic and super...Co−TiO2 nanocomposite films were prepared via magnetron sputtering at various substrate temperatures.The films comprise Co particles dispersed in an amorphous TiO2 matrix and exhibit coexisting ferromagnetic and superparamagnetic properties.When the substrate temperature increases from room temperature to 400℃,Co particles gradually grow,and the degree of Co oxidation significantly decreases.Consequently,the saturation magnetization increases from 0.13 to 0.43 T at the same Co content by increasing the substrate temperature from room temperature to 400℃.At a high substrate temperature,conductive pathways form among some of the clustered Co particles.Thus,resistivity rapidly declines from 1600 to 76μΩ·m.The magnetoresistive characteristic of Co−TiO2 films is achieved even at resistivity of as low as 76μΩ·m.These results reveal that the obtained nanocomposite films have low Co oxidation,high magnetization and magnetoresistance at room temperature.展开更多
文摘Magnetic ultrathin films were fabricated layer-by-layer using a self-assembly method through the electrostatic interaction between the photosensitive diazoresin (DR) and the negatively charged Fe 3O 4 nanoparticles (NP-Fe 3O 4).The results of the UV-vis spectra and AFM show that the assembly of DR and NP-Fe 3O 4 is very successful.After UV irradiation,the ionic bonds of the DR/NP-Fe 3O 4 film convert to covalent ones and the magnetic films become very stable toward polar solvents.The magnetic film images with good resolution are obtained by means of selective UV-exposure of the film under a photo-mask and then developing the exposed film in the saturated aqueous solution of sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB),respectively.
基金Project(2016YFE0205700)supported by the National Key Research and Development Program of ChinaProject(18JCYBJC18000)supported by the Natural Science Foundation of Tianjin City,China。
文摘Co−TiO2 nanocomposite films were prepared via magnetron sputtering at various substrate temperatures.The films comprise Co particles dispersed in an amorphous TiO2 matrix and exhibit coexisting ferromagnetic and superparamagnetic properties.When the substrate temperature increases from room temperature to 400℃,Co particles gradually grow,and the degree of Co oxidation significantly decreases.Consequently,the saturation magnetization increases from 0.13 to 0.43 T at the same Co content by increasing the substrate temperature from room temperature to 400℃.At a high substrate temperature,conductive pathways form among some of the clustered Co particles.Thus,resistivity rapidly declines from 1600 to 76μΩ·m.The magnetoresistive characteristic of Co−TiO2 films is achieved even at resistivity of as low as 76μΩ·m.These results reveal that the obtained nanocomposite films have low Co oxidation,high magnetization and magnetoresistance at room temperature.
