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1

Absorption Spectrum of Ni(II) Ions Doped in Lithium Sodium Potassium Sulphate Single Crystal

100%

Rama Kumar R., Venkata Reddy B.

Acta Physica Polonica A

|

1995

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vol. 87

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issue 6

1023-1029

EN

The optical absorption spectra of lithium sodium potassium sulphate doped Ni^{2+} ions at 300 and 77 K was recorded. The observed bands are assigned as transitions from the ground state ^{3}A_{2g}(F) to various excited triplet and singlet states of the Ni^{2+} ion in octahedral symmetry. The splittings observed for the bands ^{3}T_{1g}(F) and ^{3}T_{2g}(F) at liquid nitrogen temperature have been explained as due to spin-orbit interaction. The oscillator strengths of the transitions were computed from the area under the curves. From a detailed analysis of the bands of the spectrum, the crystal field parameters B, C, Dq and ξ are evaluated.

2

Recombination Processes for Deep Impurity States Degenerate with the Conduction Band

80%

Świątek K., Godlewski M., Kaliński Z., Przybylińska H.

Acta Physica Polonica A

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1991

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vol. 79

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issue 2-3

243-246

EN

We report on the studies of autoionization efficiency and the relevant recombination mechanism for Eu^{2+} in Ca_{x}Cd_{1-x}F_{2} depending on the energy level position of Eu^{2+} excited states in respect to the conduction band states.

3

Physics of Solid-State Laser Materials

80%

Wojtowicz A.

Acta Physica Polonica A

|

1991

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vol. 80

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issue 2

193-205

EN

A survey of the physical properties of solid state materials activated with d^{2}, d^{3} and d^{8} transition metal ions is presented in the context of tunable laser operation. An emphasis is put on common characteristics of all three systems, like a strong electron-phonon coupling and similar electronic structures. The conditions necessary to obtain a tunable operation and to avoid an overlap of the excited state absorption and emission are formulated. It is shown that the d^{3} configuration system has the largest range of allowed values of the crystal field parameter 10Dq.

4

Magnetophotoconductivity Due to Intra-Shallow-Donor Transitions in Semi-Insulating GaAs

80%

Karpierz K., Sadowski M., Grynberg M.

Acta Physica Polonica A

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1991

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vol. 80

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issue 2

291-294

EN

The paper concerns investigations of shallow centres in semi-insulating (SI) GaAs samples. A very sensitive measuring method - magnetophotoconductivity due to intra-shallow-donor transitions - was used. We report the behaviour of intra-impurity transitions as well as an additional structure in low magnetic fields for different far-infrared wavelengths (70.6 μm, 96.5 μm, 118.8 μm, 163 µm). The results are discussed in terms of a fluctuating potential from ionized centres in SI GaAs. The physical mechanism responsible for the low magnetic field structure is proposed.

5

Precipitation of Nickel Dihalide in Thermally Pretreated NaCl:Ni^{2+} Crystals

80%

Morawska-Kowal T., Nowak-Woźny D., Suszyńska M.

Acta Physica Polonica A

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1994

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vol. 86

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issue 3

363-368

EN

Optical absorption and the yield stress value of NaCl : Ni^{2+} crystals were measured as functions of the annealing temperature. Morphology and possible structure types of the NiCl_{2} particles formed under different annealing conditions have been shortly discussed.

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5 Acta Physica Polonica A

1 1995

1 1994

3 1991

1 Godlewski M.

1 Grynberg M.

1 Kaliński Z.

1 Karpierz K.

1 Morawska-Kowal T.

1 Nowak-Woźny D.

1 Przybylińska H.

1 Rama Kumar R.

1 Sadowski M.

1 Suszyńska M.

1 Venkata Reddy B.

1 Wojtowicz A.

1 Świątek K.

Absorption Spectrum of Ni(II) Ions Doped in Lithium Sodium Potassium Sulphate Single Crystal

Recombination Processes for Deep Impurity States Degenerate with the Conduction Band

Physics of Solid-State Laser Materials

Magnetophotoconductivity Due to Intra-Shallow-Donor Transitions in Semi-Insulating GaAs

Precipitation of Nickel Dihalide in Thermally Pretreated NaCl:Ni^{2+} Crystals