The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd...The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions,which possesses a cubic spinel structure with Fd3m space group.The formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions induces the obvious increase of long afterglow near infrared luminescence excited by low-dose X-ray,When the content of doped Cd^(2+)reaches 0.1,the low-dose X-ray induced long afterglow NIR luminescence is the maximum.More importantly,only 5 s Xray irradiation can induce more than 6 h NIR afterglow emission,of which the afterglow luminescent intensity is still 5 times stronger than the background intensity after 6 h.The thermoluminescent results show that under the 5 s exposure of X-ray,the trap density of Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):Cr^(3+)is much higher than that of ZnGa_(2)O_(4):Cr^(3+).The replacement of Cd^(2+)ions with large radius at Zn^(2+)sites causes the increase of de fects and dislocations,which results in the obvious increase of trap co ncentrations.And the addition of high-z number elements Cd^(2+)would enhance the X-ray absorption of the solid solutions,which thus can be easily excited by low-dose X-ray.Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):1%Cr^(3+)solid solution is a potential candidate of lowdose X-ray induced long afterglow luminescent materials.展开更多
X-ray irradiated La_(2)Ti_(2)O_(7):Pr^(3+)was found to show long-time sustainable mechanoluminescence(ML),which can realize the high sensitivity and real time detection of stress burst for more than 72 h.Under the exc...X-ray irradiated La_(2)Ti_(2)O_(7):Pr^(3+)was found to show long-time sustainable mechanoluminescence(ML),which can realize the high sensitivity and real time detection of stress burst for more than 72 h.Under the excitation of X-ray,La_(2)Ti_(2)O_(7):Pr^(3+)shows red ML emissions located at 610,624 and 638 nm,which are similar to the afterglow emission spectrum and can be ascribed to(1)^D_(2)-^(3)H_(4),^(3)P_(0)-(3)^H_(4)and (3)^P_(0)-^(3)H_(2)of Pr^(3+).And the linear increases of compressive load can induce the linear increases of ML intensity of the sample,indicating that the X-ray induced ML emission can be utilized to accurately detect the stress applied on the object.Furthermore,X-ray irradiated La_(2)Ti_(2)O_(7):Pr^(3+)possesses excellent stability and the repeatability of ML emission and the ML signals can keep stable even 50 load cycles after 1 h dacay.The thermoluminescence results suggest that abundant electrons are trapped in shallow and deep answered for stable ML emission.More importantly,the deeply trapped electrons induced ML emissions from X-ray irradiated La_(2)Ti_(2)O_(7):Pr^(3+)can be utilized to detect the stress bursts for a long time.When the sample is recharged by 5 min X-ray irradiation once,within 24 h decay,the 1500 N burst among many 1000 N cycles can be clearly detected,and the signal to noise ratio(S/N) reaches 1.32 and 1.26 after 12 and24 h decay,respectively.And even after 72 h decay,the S/N of 2500 N still arrives at 1.23 and that of4000 N reaches 1.97,indicative of long-time high sensitivity detection of abnormal stress.All these results suggest that the X-ray-irradiated La_(1.97)Ti_(2)O_(7):0.03Pr^(3+)/resin sample can realize the high sensitivity and real time detection of stress burst for more than 72 h,which thus possesses great potential application in early warning of the emergency disasters such as bridge fracture,tunnel collapse and so on.展开更多
基金Project supported by the State Key Research Project of Shandong Natural Science Foundation(ZR2020KB019)the fund of"Two-Hundred Talent"Plan of Yantai City+1 种基金the National Natural Science Foundation of China(11974013)the Natural Science Foundation of Fujian Province(2022J011270)。
文摘The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions,which possesses a cubic spinel structure with Fd3m space group.The formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions induces the obvious increase of long afterglow near infrared luminescence excited by low-dose X-ray,When the content of doped Cd^(2+)reaches 0.1,the low-dose X-ray induced long afterglow NIR luminescence is the maximum.More importantly,only 5 s Xray irradiation can induce more than 6 h NIR afterglow emission,of which the afterglow luminescent intensity is still 5 times stronger than the background intensity after 6 h.The thermoluminescent results show that under the 5 s exposure of X-ray,the trap density of Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):Cr^(3+)is much higher than that of ZnGa_(2)O_(4):Cr^(3+).The replacement of Cd^(2+)ions with large radius at Zn^(2+)sites causes the increase of de fects and dislocations,which results in the obvious increase of trap co ncentrations.And the addition of high-z number elements Cd^(2+)would enhance the X-ray absorption of the solid solutions,which thus can be easily excited by low-dose X-ray.Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):1%Cr^(3+)solid solution is a potential candidate of lowdose X-ray induced long afterglow luminescent materials.
基金Project supported by the State Key Research Projects of Shandong Natural Science Foundation (ZR2020KB019)the fund of "Two-Hundred Talent" Plan of Yantai City+1 种基金the National Natural Science Foundation of China(11974013)the Natural Science Foundation of Fujian Province (2022J011270)。
文摘X-ray irradiated La_(2)Ti_(2)O_(7):Pr^(3+)was found to show long-time sustainable mechanoluminescence(ML),which can realize the high sensitivity and real time detection of stress burst for more than 72 h.Under the excitation of X-ray,La_(2)Ti_(2)O_(7):Pr^(3+)shows red ML emissions located at 610,624 and 638 nm,which are similar to the afterglow emission spectrum and can be ascribed to(1)^D_(2)-^(3)H_(4),^(3)P_(0)-(3)^H_(4)and (3)^P_(0)-^(3)H_(2)of Pr^(3+).And the linear increases of compressive load can induce the linear increases of ML intensity of the sample,indicating that the X-ray induced ML emission can be utilized to accurately detect the stress applied on the object.Furthermore,X-ray irradiated La_(2)Ti_(2)O_(7):Pr^(3+)possesses excellent stability and the repeatability of ML emission and the ML signals can keep stable even 50 load cycles after 1 h dacay.The thermoluminescence results suggest that abundant electrons are trapped in shallow and deep answered for stable ML emission.More importantly,the deeply trapped electrons induced ML emissions from X-ray irradiated La_(2)Ti_(2)O_(7):Pr^(3+)can be utilized to detect the stress bursts for a long time.When the sample is recharged by 5 min X-ray irradiation once,within 24 h decay,the 1500 N burst among many 1000 N cycles can be clearly detected,and the signal to noise ratio(S/N) reaches 1.32 and 1.26 after 12 and24 h decay,respectively.And even after 72 h decay,the S/N of 2500 N still arrives at 1.23 and that of4000 N reaches 1.97,indicative of long-time high sensitivity detection of abnormal stress.All these results suggest that the X-ray-irradiated La_(1.97)Ti_(2)O_(7):0.03Pr^(3+)/resin sample can realize the high sensitivity and real time detection of stress burst for more than 72 h,which thus possesses great potential application in early warning of the emergency disasters such as bridge fracture,tunnel collapse and so on.
