In this paper we report the leakage current, ferroelectric and piezoelectric properties of the YFe O3 film with hexagonal structure, which was fabricated on Si（111） substrate by a simple sol-gel method. The leakage ...In this paper we report the leakage current, ferroelectric and piezoelectric properties of the YFe O3 film with hexagonal structure, which was fabricated on Si（111） substrate by a simple sol-gel method. The leakage current test shows good characteristics as the leakage current density is 5.4 × 10^-6A/cm^2 under 5 V. The dominant leakage mechanism is found to be an Ohmic behavior at low electric field and space-charge-limited conduction at high electric field region. The P–E measurements show ferroelectric hysteresis loops with small remnant polarization and coercive field at room temperature.The distinct and switchable domain structures on the nanometer scale are observed by piezoresponse force microscopy,which testifies to the ferroelectricity of the YFe O3 film further.展开更多
Based on density functional theory, using the scheme of the linearized augmented plane wave and the improved local orbital （APW＋lo）, this paper analyses and calculates the lattice parameters, formation energy and m...Based on density functional theory, using the scheme of the linearized augmented plane wave and the improved local orbital （APW＋lo）, this paper analyses and calculates the lattice parameters, formation energy and magnetism of the rare-earth permanent magnetic materials YFe12-xCrx （x = 0 - 5）. The stabilization effect and the possible positions of the substituted atom Cr are analysed. Magnetic moments for the system and the atoms are obtained.展开更多
Based on the density functional theory(DFT),using linearized augmented plane wave and improved local orbital(APW+lo),the structures and energies of Y,Fe,V,FeV,YFe12-xVx,and Y2Fe17 are optimized and calculated.It is ex...Based on the density functional theory(DFT),using linearized augmented plane wave and improved local orbital(APW+lo),the structures and energies of Y,Fe,V,FeV,YFe12-xVx,and Y2Fe17 are optimized and calculated.It is explained that the pure YFe12 with ThMn12-type structure does not exist,and replacing a small fraction of vanadium can stabilize the structure.The local magnetic moments reveal that the decrease of magnetization of YFe12-xVx does not only correspond to a simple dilution of the iron sublattice magnetization,but also reduce the Fe moments as well with increasing vanadium content.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61471301,61078057,51202195,and 511172183)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20126102110045)the NPU Foundation for Fundamental Research(Grant Nos.JC201155,JC201271,and JC20120246)
文摘In this paper we report the leakage current, ferroelectric and piezoelectric properties of the YFe O3 film with hexagonal structure, which was fabricated on Si（111） substrate by a simple sol-gel method. The leakage current test shows good characteristics as the leakage current density is 5.4 × 10^-6A/cm^2 under 5 V. The dominant leakage mechanism is found to be an Ohmic behavior at low electric field and space-charge-limited conduction at high electric field region. The P–E measurements show ferroelectric hysteresis loops with small remnant polarization and coercive field at room temperature.The distinct and switchable domain structures on the nanometer scale are observed by piezoresponse force microscopy,which testifies to the ferroelectricity of the YFe O3 film further.
基金supported by the Science and Technology Foundation of China Academy of Engineering Physics(Grant No 20050212)
文摘Based on density functional theory, using the scheme of the linearized augmented plane wave and the improved local orbital （APW＋lo）, this paper analyses and calculates the lattice parameters, formation energy and magnetism of the rare-earth permanent magnetic materials YFe12-xCrx （x = 0 - 5）. The stabilization effect and the possible positions of the substituted atom Cr are analysed. Magnetic moments for the system and the atoms are obtained.
基金supported by the Foundation of Science and Technology of China Academy of Engineering Physics (Grant No. 20040863)
文摘Based on the density functional theory(DFT),using linearized augmented plane wave and improved local orbital(APW+lo),the structures and energies of Y,Fe,V,FeV,YFe12-xVx,and Y2Fe17 are optimized and calculated.It is explained that the pure YFe12 with ThMn12-type structure does not exist,and replacing a small fraction of vanadium can stabilize the structure.The local magnetic moments reveal that the decrease of magnetization of YFe12-xVx does not only correspond to a simple dilution of the iron sublattice magnetization,but also reduce the Fe moments as well with increasing vanadium content.
