The effect of Mn_(3)O_(4)addition on microhardness,microstructure and electrical properties of vanadium oxide doped zinc oxide varistor ceramics is systematically investigated.The Vicker’s microhardness HV has decrea...The effect of Mn_(3)O_(4)addition on microhardness,microstructure and electrical properties of vanadium oxide doped zinc oxide varistor ceramics is systematically investigated.The Vicker’s microhardness HV has decreased with increasing the amount of Mn3O4.Also,the average grain size has decreased from 27.51μm to 19.55μm with increasing the amount of Mn_(3)O_(4) up to 0.50 mol%,whereas an increase in Mn_(3)O_(4) up to 0.75 mol%has caused the average grain size to increase and then it decreases with increasing Mn_(3)O_(4)from 0.75 mol%to 1.00 mol%.The sintered density has decreased from 5.38 g/cm3 to 5.31 g/cm3 with increasing the amount of Mn_(3)O_(4).The varistor ceramic modified with 0.50 mol%Mn_(3)O_(4) has exhibited excellent nonlinear properties,with 16.29 for the nonlinear coefficient and 441.9μA/cm2 for the leakage current density.Furthermore,the sample doped with 0.50 mol%Mn_(3)O_(4) has been found to possess donor density as 0.77×10^(18) cm^(-3) and 0.916 eV barrier height.展开更多
High quality epitaxial single phase（Ga_（0.96）Mn_（0.04））_2O_3 and Ga_2O_3 thin films have been prepared on sapphire substrates by using laser molecular b（eam）epitaxy（L-MBE）. X-ray diffraction results indicate...High quality epitaxial single phase（Ga_（0.96）Mn_（0.04））_2O_3 and Ga_2O_3 thin films have been prepared on sapphire substrates by using laser molecular b（eam）epitaxy（L-MBE）. X-ray diffraction results indicate that the thin films have the monoclinic structure with a 201 preferable orientation. Room temperature（RT） ferromagnetism appears and the magnetic properties of β-（Ga_（0.96）Mn_（0.04））_2O_3 thin film are enhanced compared with our previous works. Experiments as well as the first principle method are used to explain the role of Mn dopant on the structure and magnetic properties of the thin films. The ferromagnetic properties are explained based on the concentration of transition element and the defects in the thin films.展开更多
文摘The effect of Mn_(3)O_(4)addition on microhardness,microstructure and electrical properties of vanadium oxide doped zinc oxide varistor ceramics is systematically investigated.The Vicker’s microhardness HV has decreased with increasing the amount of Mn3O4.Also,the average grain size has decreased from 27.51μm to 19.55μm with increasing the amount of Mn_(3)O_(4) up to 0.50 mol%,whereas an increase in Mn_(3)O_(4) up to 0.75 mol%has caused the average grain size to increase and then it decreases with increasing Mn_(3)O_(4)from 0.75 mol%to 1.00 mol%.The sintered density has decreased from 5.38 g/cm3 to 5.31 g/cm3 with increasing the amount of Mn_(3)O_(4).The varistor ceramic modified with 0.50 mol%Mn_(3)O_(4) has exhibited excellent nonlinear properties,with 16.29 for the nonlinear coefficient and 441.9μA/cm2 for the leakage current density.Furthermore,the sample doped with 0.50 mol%Mn_(3)O_(4) has been found to possess donor density as 0.77×10^(18) cm^(-3) and 0.916 eV barrier height.
基金Project supported by the National Natural Science Foundation of China(Nos.11404029,51572033,51172208)the Fund of State Key Laboratory of Information Photonics and Optical Communications(BUPT)
文摘High quality epitaxial single phase（Ga_（0.96）Mn_（0.04））_2O_3 and Ga_2O_3 thin films have been prepared on sapphire substrates by using laser molecular b（eam）epitaxy（L-MBE）. X-ray diffraction results indicate that the thin films have the monoclinic structure with a 201 preferable orientation. Room temperature（RT） ferromagnetism appears and the magnetic properties of β-（Ga_（0.96）Mn_（0.04））_2O_3 thin film are enhanced compared with our previous works. Experiments as well as the first principle method are used to explain the role of Mn dopant on the structure and magnetic properties of the thin films. The ferromagnetic properties are explained based on the concentration of transition element and the defects in the thin films.
