Impact of grain size,Pr3+ concentration and host composition on non-contact temperature sensing abilities of polyphosphate nano- and microcrystals  

作　　者：S.Gharouel L.Marciniak A.Lukowiak W.Strek K.Horchani-Naifer M.Férid 

机构地区：[1]Research Unit of Rare Earth Materials,National Research Center in Sciences of Materials,B.P.95 Hammam-Lif,2050,Tunisia b Institute of Low Temperature and Structure Research,PAS [2]Okolna St.,50-422,Wroclaw,Poland

出　　处：《Journal of Rare Earths》2019年第8期812-818,I0001,共8页稀土学报（英文版）

基　　金：Project supported by the Ministry of Higher Education and Scientific Research in Tunisia(99/UR/07-03)

摘　　要：In this article,varied praseodymium polyphosphate hosts:MI(Li,Na K)Pr(PO3)4 microcrystals and LiLa1-xPrx(PO3)4(x = 0.01 ^-1)nanocrystals were successfully synthesized by the flux method and the coprecipitation technique,respectively.The size of stoichiometric nanocrystals of LiPr(PO3)4 was tuned by the te mpe rature of thermal treatment in range of 35-145 nm.In order to dete rmine the most suitable material for the non-contact optical thermometric applications,the temperature sensing measurements were carried out by using luminescence intensity ratio(LIR)of emission bands corresponding to the ^3 P1→ ^3H5 and ^3P0→ ^3 H5 electronic transitions of Pr3+ ions into the 123-423 K temperature range.The influence of the host material composition of MⅠ(Li,Na,K)Pr(PO3)4 microcrystals on the sensitivity of luminescent thermometers was studied.It is found that the sensitivity of lithium praseodymium polyphosphate is the highest of all micropowders under investigation.Moreover,it is found that the nanocrystals reveal much higher relative sensitivity in respect to the microcrystalline counterparts.The highest sensitivity of LIR temperature sensing is found for LiPr(PO3)4 nanocrystals(35 nm grain size)in the whole temperature range,reaching 0.283%/K at 164 K.The impact of the average grain size on the sensitivity of LIR based thermometers of LiPr(PO3)4 nanocrystals was investigated.It is found that the reduction of the grain size from 145 to 35 nm results in the enhancement of the relative sensitivity from0.156 to 0.240%/K at 223 K.Additionally it is found that the high dopant concentration possesses favorable influence on the relative sensitivity of LiLa1-xPrx(PO3)4 nanocrystalline luminescent thermometers.In this article,varied praseodymium polyphosphate hosts:MI（Li,Na K）Pr（PO3）4 microcrystals and LiLa1-xPrx（PO3）4（x = 0.01-1）nanocrystals were successfully synthesized by the flux method and the coprecipitation technique,respectively.The size of stoichiometric nanocrystals of LiPr（PO3）4 was tuned by the te mpe rature of thermal treatment in range of 35-145 nm.In order to dete rmine the most suitable material for the non-contact optical thermometric applications,the temperature sensing measurements were carried out by using luminescence intensity ratio（LIR）of emission bands corresponding to the 3 P1→3H5 and 3P0→3 H5 electronic transitions of Pr3+ ions into the 123-423 K temperature range.The influence of the host material composition of MⅠ（Li,Na,K）Pr（PO3）4 microcrystals on the sensitivity of luminescent thermometers was studied.It is found that the sensitivity of lithium praseodymium polyphosphate is the highest of all micropowders under investigation.Moreover,it is found that the nanocrystals reveal much higher relative sensitivity in respect to the microcrystalline counterparts.The highest sensitivity of LIR temperature sensing is found for LiPr（PO3）4 nanocrystals（35 nm grain size）in the whole temperature range,reaching 0.283%/K at 164 K.The impact of the average grain size on the sensitivity of LIR based thermometers of LiPr（PO3）4 nanocrystals was investigated.It is found that the reduction of the grain size from 145 to 35 nm results in the enhancement of the relative sensitivity from0.156 to 0.240%/K at 223 K.Additionally it is found that the high dopant concentration possesses favorable influence on the relative sensitivity of LiLa1-xPrx（PO3）4 nanocrystalline luminescent thermometers.

关 键 词：PR^3+ TEMPERATURE sensing Luminescence intensity ratio TEMPERATURE sensitivity Grain size Dopant CONCENTRATION 

分 类 号：O61[理学—无机化学]