Research On Structure,luminescent And Hydration Properties Of Rare Earth (Gd³⁺,Tb³⁺,Eu³⁺) Doped Tricalcium Phosphate

This thesis systematically studied the structure,luminescence and hydration-properties of rare earth(Gd3+,Tb3+.Eu3+)doped tricalcium phosphate(TCP).Tricalcium phosphate doped with different concentrations of Gd3+,Tb3+ and Eu3+ ions was synthesized by high temperature solid phase method combined with air quenching and furnace cooling.The structural analysis shows that with the increase of the doping amount of Gd3+,Tb3+ and Eu3+ ions,the crystal form of the TCP sample transitions from pure a phase to pure ? phase.The solution limit of Gd3+,Tb3+and Eu3+ions in ?-TCP is higher than that in ?-TCP,and the doping of Gd3+,Tb3+and Eu3+ions could significantly improve the thermal stability of ?-TCP.Compared with air quenching,furnace cooling could promote the conversion of ?-TCP to ? phase during cooling,and the doping of Gd3+,Tb3+and Eu3+ions could accelerate the transformation.In terms of luminous performance,the TCP:Gd samples emits ultraviolet light and the TCP:Tb samples emits green light.In addition,with the increase of doped concentration,the concentration quenching phenomenon occurs.In the TCP:Eu samples,due to the partial self-reduction of Eu3+ ions in the a phase the luminous color of the sample gradually changes from blue-green light to orange-red.Hydration experimental results show that TCP:1%Gd,TCP:1%Tb and TCP:1%Eu can be hydrated to form hydroxyapatite after immersion in dilute phosphate solution for 168h?240h,and shows good biological activity.Moreover.EDS results confirmed that only part of the Gd3+,Tb3+and Eu3+ions entered the HA lattice;the luminous intensity of the hydration product gradually decreased with the extension of the hydration time,so the luminous intensity of Gd3+,Tb3+and Eu2+/3+ions can be used to monitor the hydration progress of ?-TCP.In addition,the luminescence color of TCP:1%Eu hydration product gradually changed from blue-green to orange-red with the extension of the hydration time,so the formation of HA can be simply and effectively monitored by the change of luminescence color of Eu2+/3+ ions.