Estudo de propriedades estruturais e de piezeletricidade nos cristais de ADP e KDP puros e dopados com íons Ni2+ e Mn3+ com DMRX utilizando radiação síncrotron
The X-ray multiple diffraction using synchrotron radiation has been applied to study transition metal cátions Mn 3+ and Ni 2+ incorporated into Ammonium Diydrogen Phosphate (ADP) Crystal lattice and potassium dihydrogen phosphate (KDP). The results shows that regarding peak positions and number of p...
| Autor principal: | GOMES, Eduardo José de Lima |
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| Grau: | Dissertação |
| Idioma: | por |
| Publicado em: |
Universidade Federal do Pará
2014
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| Acesso em linha: |
http://repositorio.ufpa.br/jspui/handle/2011/5075 |
| Resumo: |
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The X-ray multiple diffraction using synchrotron radiation has been applied to study transition metal cátions Mn 3+ and Ni 2+ incorporated into Ammonium Diydrogen Phosphate (ADP) Crystal lattice and potassium dihydrogen phosphate (KDP). The results shows that regarding peak positions and number of peaks all the profilets look almost identical. This fact alone tells us that the unit cell parameters and the crystal symmetry are practically the same regardless of the incorporation of Mn 3+ and Ni 2+ cations. Accurate calculation of the unit-cell parameters revels that the lattices lattices parameters a = b increase and lattices parameters c decrease following Ni 2+ and Mn 3+ incorporation. In the measurements for the two wavelengths ADP:Mn crystal exhibit asymmetric peak profiles and no extra peak appears in the whole Mn 3+ doped RS. On the other hand, in the ADP:Ni measurements one can clearly observe: (i) suppression of the intensity profile asymmetry in secondary peaks for the Ni 2+ doped RS (below l Ni 2+ Kedge) and also, (ii) marked asymmetry inversion (above l Ni 2+ Kedge), for example the peak (5-12) / (-112) which represents a four beam case. These results indicate that synchrotron radiation RS is a high resolution probe to be used in the impurity incorporation in the ADP lattice. Moreover we have investigated ADP:Mn, KDP:Mn and KDP:Ni crystals using X-ray diffraction at room temperature. The results of the measurements of 440 and 066 reflections allow obtaining the d 36 and d 25 coefficients. We reported on the experimental verification based on X-ray measurements, the d 36 piezoelectric coefficients increased with doping of the Mn and Ni 2+ in the KDP and in ADP crystals. |