Infrared Radiation Performance And First-principles Study Of B-doped Aluminate

Infrared radiation material is a new functional material with the development of infrared radiation technology,which is widely used in energy saving,environmental protection,industrial heating,medical and other fields.Lanthanum aluminate has good lattice matching,thermal expansion coefficient is small,chemical stability is good,wide bandgap width,good thermal stability,therefore,this experiment selects the lanthanum aluminate matrix material by sol-gel method at 1500? for the preparation of pure LaAlO3 and doped LaAlO3,infrared radiation properties of materials,and the electronic structure and optical properties of LaAlO3 and doped LaAlO3 were calculated by using CASTEP module in Materials Studio simulation software to study the electron transition mechanism.The main results are as follows:The prepared LaAl1-xFexO3 has a single perovskite structure.The morphology of lanthanum aluminate is changed,the agglomeration is reduced,and the shape is spherical.When the doping amount of x=0.50,the average emissivity of lanthanum aluminate in the near infrared band is 0.706,compared with the pure LaAlO3(0.203),increased by 247%,in addition,its emissivity in the mid infrared band also increased.The electronic structure and optical properties of LaAlO3 and Fe:LaAlO3 were analyzed.After the Fe atom is doped,the band gap of LaAlO3 is reduced from3.496 eV to 0.974 eV,and a new peak appears at the bottom of the conduction band,which is the impurity energy formed by the p-orbital hybridization of the d-orbit of the Fe atom level.The prepared LaAl1-xNixO3 also has a single perovskite structure.The morphology of lanthanum aluminate is changed,the agglomeration is obviously reduced,the grain is refined,the development is complete,and the shape is spherical.When the doping amount of x=0.25,the average emissivity of lanthanum aluminate in the near infrared band is 0.885,compared with the pure LaAlO3(0.203),increased by 335%,in addition,the infrared emissivity in the mid infrared band is also greatly improved.The electronic structure and optical properties of Ni: LaAlO3 were analyzed.After the Ni atom is doped,the band gap of LaAlO3 is obviously reduced,and a new peak appears at the bottom of the conduction band,which is the impurity level formed by the porbital hybridization of the d-orbit of the Ni atom.The prepared LaAl0.75-xNi0.25FexO3 still has a single perovskite structure.The morphology of lanthanum aluminate is changed,the agglomeration is obviously reduced,the grain is refined,the development is complete,and the shape is spherical.When the doping amount of lanthanumaluminate x=0.25,average emission in the near infrared band rate was 0.901,compared to the pure LaAlO3,and lanthanum aluminate doped with Ni2+ and Fe3+ respectively,has been greatly improved,in addition,in the middle and far infrared with high emissivity.The electronic structure and optical properties of Ni-Fe: LaAlO3 were analyzed.After doping,the bandgap width of LaAlO3 decreases,and a new peak appears at the bottom of the conduction band,which is the Niatom,the d-orbital of the Fe atom and the p-orbital hybridization of the O atom.The band gap is reduced,the number of tracks occupied by the impurity level in the forbidden band increases,and the energy required for the transition from the valence band to the conduction band is reduced,the free carrier concentration in the forbidden band increases and the free carrier absorption increases,the infrared emissivity of the material is improved.