Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl<sub>2</sub>O<sub>4</sub> Ceramics
Herein we demonstrate the specifics of using the positron annihilation lifetime spectroscopy (PALS) method for the study of free volume changes in functional ceramic materials. Choosing technological modification of nanostructured MgAl<sub>2</sub>O<sub>4</sub> spinel as an ex...
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| Format: | Article |
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MDPI AG
2021-12-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/11/12/3373 |
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| author | Halyna Klym Ivan Karbovnyk Sergei Piskunov Anatoli I. Popov |
| author_facet | Halyna Klym Ivan Karbovnyk Sergei Piskunov Anatoli I. Popov |
| author_sort | Halyna Klym |
| collection | DOAJ |
| description | Herein we demonstrate the specifics of using the positron annihilation lifetime spectroscopy (PALS) method for the study of free volume changes in functional ceramic materials. Choosing technological modification of nanostructured MgAl<sub>2</sub>O<sub>4</sub> spinel as an example, we show that for ceramics with well-developed porosity positron annihilation is revealed through two channels: positron trapping channel and ortho-positronium decay. Positron trapping in free-volume defects is described by the second component of spectra and ortho-positronium decay process by single or multiple components, depending on how well porosity is developed and on the experimental configuration. When using proposed positron annihilation lifetime spectroscopy approaches, three components are the most suitable fit in the case of MgAl<sub>2</sub>O<sub>4</sub> ceramics. In the analysis of the second component, it is shown that technological modification (increasing sintering temperature) leads to volume shrinking and decreases the number of defect-related voids. This process is also accompanied by the decrease of the size of nanopores (described by the third component), while the overall number of nanopores is not affected. The approach to the analysis of positron annihilation lifetime spectra presented here can be applied to a wide range of functional nanomaterials with pronounced porosity. |
| first_indexed | 2024-03-10T03:26:21Z |
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| id | doaj.art-6f732bf91e7c400bbd17010aeb1c5a81 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-10T03:26:21Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
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| series | Nanomaterials |
| spelling | doaj.art-6f732bf91e7c400bbd17010aeb1c5a812023-11-23T09:51:41ZengMDPI AGNanomaterials2079-49912021-12-011112337310.3390/nano11123373Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl<sub>2</sub>O<sub>4</sub> CeramicsHalyna Klym0Ivan Karbovnyk1Sergei Piskunov2Anatoli I. Popov3Specialized Computer Systems Department, Lviv Polytechnic National University, 12 Bandera Str., 79013 Lviv, UkraineSpecialized Computer Systems Department, Lviv Polytechnic National University, 12 Bandera Str., 79013 Lviv, UkraineInstitute for Solid State Physics, University of Latvia, Kengaraga 8, LV-1063 Riga, LatviaInstitute for Solid State Physics, University of Latvia, Kengaraga 8, LV-1063 Riga, LatviaHerein we demonstrate the specifics of using the positron annihilation lifetime spectroscopy (PALS) method for the study of free volume changes in functional ceramic materials. Choosing technological modification of nanostructured MgAl<sub>2</sub>O<sub>4</sub> spinel as an example, we show that for ceramics with well-developed porosity positron annihilation is revealed through two channels: positron trapping channel and ortho-positronium decay. Positron trapping in free-volume defects is described by the second component of spectra and ortho-positronium decay process by single or multiple components, depending on how well porosity is developed and on the experimental configuration. When using proposed positron annihilation lifetime spectroscopy approaches, three components are the most suitable fit in the case of MgAl<sub>2</sub>O<sub>4</sub> ceramics. In the analysis of the second component, it is shown that technological modification (increasing sintering temperature) leads to volume shrinking and decreases the number of defect-related voids. This process is also accompanied by the decrease of the size of nanopores (described by the third component), while the overall number of nanopores is not affected. The approach to the analysis of positron annihilation lifetime spectra presented here can be applied to a wide range of functional nanomaterials with pronounced porosity.https://www.mdpi.com/2079-4991/11/12/3373nanostructured ceramicspositron annihilationpositronium decaypositron trappingfree-volume defectsnanopores |
| spellingShingle | Halyna Klym Ivan Karbovnyk Sergei Piskunov Anatoli I. Popov Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl<sub>2</sub>O<sub>4</sub> Ceramics Nanomaterials nanostructured ceramics positron annihilation positronium decay positron trapping free-volume defects nanopores |
| title | Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl<sub>2</sub>O<sub>4</sub> Ceramics |
| title_full | Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl<sub>2</sub>O<sub>4</sub> Ceramics |
| title_fullStr | Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl<sub>2</sub>O<sub>4</sub> Ceramics |
| title_full_unstemmed | Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl<sub>2</sub>O<sub>4</sub> Ceramics |
| title_short | Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl<sub>2</sub>O<sub>4</sub> Ceramics |
| title_sort | positron annihilation lifetime spectroscopy insight on free volume conversion of nanostructured mgal sub 2 sub o sub 4 sub ceramics |
| topic | nanostructured ceramics positron annihilation positronium decay positron trapping free-volume defects nanopores |
| url | https://www.mdpi.com/2079-4991/11/12/3373 |
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