YAP, S.V., RANSON, R.M., CRANTON, W.M., KOUTSOGEORGIS, D.C. and HIX, G.B., 2009. Temperature dependent characteristics of La2O2S: Ln [Ln = Eu,Tb] with various Ln concentrations over 5-60 ºC. Journal of Luminescence, 129 (5), pp. 416-422.
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This research is aimed at developing an optical sensor for remotely measuring human skin temperature in electromagnetically hostile environments, such as within a magnetic resonance imaging (MRI) scanner. In this feasibility study, various concentrations of europium doped lanthanum oxysulphide (La2O2S: Eu- 0.1-15 mol % (m/o)) and terbium doped lanthanum oxysulphide (La2O2S: Tb - 0.005-50 m/o) have been investigated in terms of crystallinity, photoluminescent (PL) spectral and decay time characteristics. For both phosphors, X-ray diffraction (XRD) has shown that as dopancy increases, the (100) and (002) reflections merge and there is a reduction in the c-axis parameter as well as the crystallite size. Photoluminescent characterisation (337 nm excitation) has also shown a dependency to dopant concentration through variance of peak intensity. Temperature dependent decay time measurements were carried out over a low temperature range of 5 to 60 °C. Optimum brightness of these temperature dependent lines is achieved at concentrations of 1 and 10 m/o for La2O2S: Eu and La2O2S: Tb respectively. However, optimum temperature dependency is achieved at lower concentration for La2O2S: Eu, specifically at 0.1 m/o. In comparison to conventional phosphor temperature dependent characteristic, La2O2S: Tb showed an increase in decay time with respect to temperature for concentrations above 2 m/o.
|Item Type:||Journal article|
|Publication Title:||Journal of Luminescence|
|Creators:||Yap, S.V., Ranson, R.M., Cranton, W.M., Koutsogeorgis, D.C. and Hix, G.B.|
|Divisions:||Schools > School of Science and Technology|
|Depositing User:||EPrints Services|
|Date Added:||09 Oct 2015 10:04|
|Last Modified:||17 Jan 2017 10:32|
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