Study On The Optical And Electrical Properties Of Mn-Ni-Zn-O NTC Thermosensitive Film Materials

Manganese-based heat-sensitive oxide with spinel structure has excellent sensitivity to temperature and is widely used in the manufacture of heat-sensitive devices.The preparation of manganese-based heat-sensitive film is of great significance to the microstructure,surface morphology,optical and electrical properties of the film.Prior to this,a large amount of research has been conducted on Zn-doped manganese-based heat-sensitive oxide materials.However,the research on the prepared thin film materials is rare by doping Zn element on the basis of NiMn₂O₄.And whether Zn is occupying the A or B position of spinel in manganese nickel oxide has been controversial.Therefore,a manganese-based heat-sensitive oxide material doped with Zn is used in this thesis and the properties of Mn-Ni-Zn-O films were investigated.In this thesis,Mn-Ni-Zn-O thermal film was prepared by magnetron sputternng for Mn-Ni-Zn alloy target,and the basic process parameters were optimized.The effects of different sputtering conditions on the microstructure,surface morphology,Raman properties and electrical properties of the films were investigated.At the same time,Mn_1.56Co_0.96Ni_0.48-xZn_xO₄?x=0,0.05,0.1,0.15,0.2,0.3?thin film materials were prepared by chemical solution deposition method.And the structure and surface morphology and photoelectric properties of the material were tested.The specific results are as follows:?1?The MNZ film was prepared by magnetron sputternng,and it was found that the film having an annealing temperature of 750 ? had good crystallinity.It is also concluded that Zn ions may occupy the A and B sites of the spinel structure,and the conduction mechanism of the Mn₂Ni_o.sZn_o.2O₄ film is the nearest neighbor jump.After optimizing the sputtering power,it is found that the film with a sputtering power of 200W is of good quality.After optimizing the argon-oxygen ratio in the sputtering atmosphere,the content of Mn²⁺ and Mn⁴⁺ in the film increased under aerobic conditions,but the content of Mn³⁺ did not change much.Therefore,the ratio of Mn³⁺/Mn⁴⁺ is closer to 1,indicating that the addition of oxygen to the sputtering atmosphere enhances the electrical conductivity of the film.?2?The effect of Zn ion content on MCNZ film was studied by chemical solution deposition method.It is found that Zn ions instead of Ni ions occupy the A-site of the spinel when a small amount of Zn ions are doped,and as the Zn content increases,the Zn ions occupy the B-site of the spinel.At the same time,the thermal constant B value of the MCNZ film changed from 3708K to 5424K.Therefore,the sensitivity of the target film can be obtained by adjusting the content of Zn ions.