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您的检索式：作者名="L.Marciniak"
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| 1 | Laser induced broad band anti-Stokes white emission from LiYbF_4 nanocrystals显示文摘Spectroscopic properties of tetragonal LiYbF_4 nanocrystals under high dense NIR excitation at vacuum condition were investigated. White, broad band emission covering whole visible part of the spectrum from LiYbF_4 nanocrystals was observed. Its intensity strongly depended on the excitation power, excitation wavelength and ambient pressure. Temperature of the nanocrystals under 975 nm excitation was determined as a function of excitation power. Strong photo-induced current was observed from LiYbF_4 pallet. The emission kinetic was analyzed. The mechanism of the anti-Stokes white emission was discussed in terms of the laser-induced charge transfer emission from Yb^(2+) states. | L.Marciniak R.Tomala M.Stefanski D.Hreniak W.Strek | 2016 | Journal of Rare Earths2016，34，3： | 2 |
| 2 | Luminescence investigation of Dy2O2S and Dy2O2SO4 obtained by thermal decomposition of sulfate hydrate显示文摘The yellow emitting dysprosium oxysulfide(Dy_2O_2S) and dysprosium oxysulfate(Dy_2O_2SO_4) compounds were prepared from the thermal decomposition of hydrated dysprosium sulphate. The materials were characterized by using thermogravimetry(TG/DTG), X-ray powder diffraction(XRD), Fourier transform infrared(FTIR) and Raman spectroscopies. The thermal stability temperatures at around 1151 and 1313 K were determined for the Dy2O2 S and Dy_2O_2SO_4 materials, respectively. The photoluminescence properties of the dysprosium oxysulfide were investigated, showing narrow emission bands assigned to the ~4F_(9/2)→6H_J intraconfigurational transitions of the Dy^(3+) ion. The yellow emission color of this phosphor suggests that the Dy_2O_2S is a promising material for applications in LEDs. | R.V.Rodngues L.Marciniak L.U.Khan J.R.Matos H.F.Brito W.Strek | 2016 | Journal of Rare Earths2016，34，8： | 1 |
| 3 | Governing of down-shifting processes in LiLaP_4O_(12):Tb^(3+),Yb^(3+) for enhancement of its near-infrared emission显示文摘Downshifting behavior of the Tb^(3+)-Yb^(3+) co-doped nanocrystalline LiL aP 4O12 powders synthesized by co-precipitation method was presented and discussed. The structural phase purity of obtained material was confirmed by X-ray diffraction(XRD)measurements. Strong enhancement of ytterbium 2~F_(5/2)→~2F_(7/2) emission intensity was observed with decreasing Tb^(3+) concentration under UV excitation. Dependence of efficiency of energy transfer between dopants on pumping wavelength was investigated due to better understanding of down-shifting mechanism. It was found that luminescence intensity of Yb^(3+) decreased above 10 mol.% dopant content, what was caused by concentration quenching. The power dependence measurements were carried out at 77 and 300 K. The resulting slopes had the same value of 1, what indicated the existence of linear down-shifting process, independent of the temperature. | K.Grzeszkiewicz L.Marciniak D.Hreniak | 2016 | Journal of Rare Earths2016，34，8： | 0 |
| 4 | Impact of grain size,Pr3+ concentration and host composition on non-contact temperature sensing abilities of polyphosphate nano- and microcrystals显示文摘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. | S.Gharouel L.Marciniak A.Lukowiak W.Strek K.Horchani-Naifer M.Férid | 2019 | Journal of Rare Earths2019，37，8： | 0 |
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