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1
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Specific Features of Strengthening Phenomena in NaCl:Eu^{2+} Crystals

100%
Suszyńska M.
Acta Physica Polonica A
|
1991
|
vol. 79
|
issue 4
493-500
EN
Mechanical strength of europium doped NaCl crystals was studied as a function of both the dopant concentration (c_{2+}) and the kind of obstacles effective in hindering the motion of dislocations. It has been found that the yield strength (σ_{0}) of solution treated samples is determined by Snoek reorientation of both isolated dipoles and linear dimers within the stress fields of moving dislocations. The deviation of the σ_{0} (c_{2+}) plot from linearity is probably due to the presence of quadripoles cutted through the moving dislocations. Also for as- received specimens two precipitation strengthening mechanisms are postulated; these are the Kelly-Nicholson cutting and the Orowan looping, respectively.
2
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Investigations of Defect Centres in Alkali Halides Doped with Trivalent Cations. Part 1: Bismuth in NaCl, KCl and RbCl Crystals

63%
Suszyńska M., Capelletti R.
Acta Physica Polonica A
|
1993
|
vol. 83
|
issue 1
25-38
EN
A correlated set of experiments was performed with a view to study the effect of trivalent bismuth upon some properties of NaCl, KCI and RbCI crystals. For NaCI the effect of BiO^{+} ions was also investigated. It was stated that: 1. The hydrolytic properties of bismuth are responsible for the formation of BiO^{+} centres also in crystals doped with BP^{3+} ions. 2. During all experiments performed, the dopant remains in the form of trivalent cations. 3. Optical absorption spectra of bismuth are similar to those characteristic of other heavy metal ions with the s^{2} electronic configuration. 4. The charge excess of BP^{3+} ions is compensated by cation vacancies whereas for BiO^{+} ions the preferential bonding between Bi^{3+} and O^{2-} serves for the charge compensation.
3
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Thermally-Induced Depolarization Current Spectra of NaCl:Ni^{2}+ Crystals

63%
Suszyńska M., Capelletti R.
Acta Physica Polonica A
|
1991
|
vol. 80
|
issue 1
129-139
EN
The technique of thermally stimulated depolarization currents was exploited to search dipolar defects in NaCl crystals doped with divalent nickel in a wide concentration range. The results were critically compared with those typical of other impurities. It has been shown that the main features of the detected polarizations are qualitatively similar to those characteristic of alkali halides doped with divalent cations. The differences observed in some instances can be understood in terms of different mobility and/or stability of the elementary defects related with the impurities.
4
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Investigations of Defect Centres in Alkali Halides Doped with Trivalent Cations. Part 2: The NaCl:Cr^{3+} Crystals

63%
Suszyńska M., Capelletti R.
Acta Physica Polonica A
|
1993
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vol. 83
|
issue 1
39-49
EN
On the basis of ITC studies, complemented by some spectroscopic and ionic conductivity measurements, it was stated that dielectric relaxations of the NaCl:Cr^{3+} crystals are more complicated than those typical of AH:Me^{2+} systems. The complexity of these phenomena concerns the number, shape and positions of the bands appearing in the ITC spectrum. The origin of the main peaks was discussed in terms of relaxations related with the chromium centres; substitutionally and off-center located Cr3^{+} ions, accompanied by two cation vacancies at geometrically different positions, and Cr clusters distributed around dislocations were considered.
5
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Some Structure-Sensitive Properties of NaCl:Ni^{2+} Crystals

63%
Nowak-Woźny D., Suszyńska M.
Acta Physica Polonica A
|
1992
|
vol. 81
|
issue 3
419-427
EN
The effect of thermal treatment upon the yield strength and some optical absorption parameters were investigated for NaCl crystals containing different amount of divalent nickel. It has been shown that the main changes of the structure-sensitive characteristics occur in two temperature ranges. In the low-temperature range (room temperature-473 K) the yield strength of crystals does change drastically whereas the optical parameters of annealed samples become similar to those characteristic of as-received crystals. On the other hand, the high-temperature annealings (473-673 K) mainly affect the optical characteristics remaining the mechanical ones - more or less similar to those typical of the solution treated state. Some correlations of these effects with the morphology of possible nickel clusters have been shortly discussed.
6
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Structural and Optical Characterisation of Hydrogenated Soda-Lime Silicate Glasses Doped with Silver and Copper

51%
Suszyńska M., Krajczyk L., Macalik B.
Acta Physica Polonica A
|
2003
|
vol. 104
|
issue 6
559-569
EN
The results of comparative studies of the effect of hydrogenation upon structural and optical properties of the commercial soda-lime silicate glasses doped either with monovalent silver or copper have been presented. The samples were characterised by means of the scanning and transmission electron microscopy and the UV-VIS-IR absorption spectroscopy. It has been shown that the annealing of suitably ion-exchanged specimens in gaseous hydrogen atmosphere could be considered as an effective procedure for obtaining composite materials of expected properties correlated with the induced changes of the morphology of both the glassy matrix and the dopant.
7
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Precipitation of Nickel Dihalide in Thermally Pretreated NaCl:Ni^{2+} Crystals

51%
Morawska-Kowal T., Nowak-Woźny D., Suszyńska M.
Acta Physica Polonica A
|
1994
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vol. 86
|
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.
8
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Impurity-Induced Strengthening Phenomena in Alkali Halide Crystals

51%
Nowak-Wożny D., Suszyńska M., Szmida M.
Acta Physica Polonica A
|
1991
|
vol. 79
|
issue 6
915-920
EN
It has been shown that divalent impurities (Sr^{2+} ,Eu^{2+}) harden the NaCl monocrystals intensively. For the solution treated samples the effective obstacles and interaction mechanisms are nearly the same for both crystal systems. In contrary, because of some differences in the solubility limit and in the clustering phenomena as well, different interaction mechanisms determine-the crystal strength attainable in as-received samples.
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