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High pressure spectroscopy of Pr3+ doped KLa(MoO4)2 crystal

Galanciak D, Gryk W, Grinberg M, Macalik L, Mączka M

Optica Applicata

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2006

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Vol. 36, nr 4

s. 443--450

EN

Optical properties and electronic structure of Pr3+ ion in KLa0.75Pr0.25(MoO4)2 have been investigated. The standard spectroscopy (excitation and photoluminescence spectra) and the high pressure spectroscopy methods have been used. Hydrostatic pressure up to 100 kbar has been applied in diamond anvil cell. The luminescence related to the transitions from the 3P0 and 1D2 states have been measured at ambient temperature for different pressures. We have found that the pressure shifts of the observed emission lines are negative and equal to 2–3 cm–1/kbar. It is due to the changes in Slater and α, β, γ parameters and diminishing of the spin-orbit coupling constant ζ.

2

Synthesis and characterization of metastable CeO2-ZrO2 solid solution obtained by polymerized complex method

Miśta W., Rayment T., Hanuza J., Macalik L.

Materials Science Poland

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2004

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Vol. 22, No. 2

153--170

EN

The paper describes the preparation and characterization of nano-size metastable tetragonal CeO2–ZrO2 mixed oxides prepared by a polymerized complex method. A glycine–ethylene glycol solution containing Ce3+ and Zr4+ ions was polymerized at 80–110 °C to form a viscous transparent resin without any visible precipitation. After heat-treatment at relatively low temperature (ca 250 °C) on a hot plate in static air, the solid precursor ignited in part due to self-combustion, resulting in the formation of a nanocrystalline, compositionally-homogeneous solid solution. Its structure was confirmed using X-ray diffraction, HRTEM and Raman spectroscopy. The phase separation in CeO2–ZrO2 system on a subsequent heat-treatment in air and in a mixture of H2 and He was also investigated up to 1100 °C.

3

Luminescence properties of Eu3+-doped Al2(WO4)3

Macalik L., Hanuza J., Hermanowicz K., Godlewska P., Sidorov N. V.

Materials Science Poland

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2004

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Vol. 22, No. 2

145--152

EN

Emission spectra of Al2(WO4)3 doped with Eu3+ were recorded at room temperature (orthorhombic phase) and at 10 K (monoclinic phase). The luminescence excitation spectra and luminescence decay profiles were recorded for both structural modifications at RT and LN2T, and the luminescence lifetimes of Eu3+ have been estimated. Two-site behaviour of the optically active ions in both phases has been revealed in the luminescence studies. However, the emission decay profiles give one lifetime of the 5D2 level, equal to 1.8 ms and 848.4 žs at room temperature and liquid nitrogen temperature, respectively. The results obtained have been explained in terms of an unusual location of Eu3+ ions inside the crystal tunnels, parallel to the c-axis.

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The bismuth - doping effect on the Jahn-Teller phase transition in CsDy(MoO4)2 crystal

Gerashchenko S. S., Miloslavskaya O. V., Kharchenko Y. N., Kut'ko V. I., Nesterenko N. M., Macalik L., Hermanowicz K., Mączka M., Hanuza J.

Materials Science

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2002

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Vol. 20, No. 2

81-89

EN

Using spectroscopic and visual optical methods the shift of the critical temperature (Ttr~42K) of the first-order phase transition of the Jahn-Teller type to the lowtemperature side at doping the CsDy(MoO4)2 crystal with Bi3+ (concentration up to x~0.08) was revealed. Effect of the doping is compared to the effect of uniaxial pressure. Using the result of the Zeeman effect we have calculated the critical value Hc of external magnetic field at which the spontaneous change of the sizes of crystal is suppressed under magnetic field and the high-temperature phase may be induced at T=0°K. It is supposed that doping with Bi3+ leads to decrease of the critical magnetic field value for doped CsDy(MoO4)2 .